diff --git a/slither/__main__.py b/slither/__main__.py
index 9ccca453c..ec184d3ba 100644
--- a/slither/__main__.py
+++ b/slither/__main__.py
@@ -78,7 +78,10 @@ def process_truffle(dirname, args, detector_classes, printer_classes):
                 package = json.load(f)
                 if 'devDependencies' in package:
                     if 'truffle' in package['devDependencies']:
-                        truffle_version = 'truffle@{}'.format(package['devDependencies']['truffle'])
+                        version = package['devDependencies']['truffle']
+                        if version.startswith('^'):
+                            version = version[1:]
+                        truffle_version = 'truffle@{}'.format(version)
                         cmd = ['npx', truffle_version,'compile']
     logger.info("'{}' running (use --truffle-version truffle@x.x.x to use specific version)".format(' '.join(cmd)))
     process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
diff --git a/slither/analyses/data_dependency/data_dependency.py b/slither/analyses/data_dependency/data_dependency.py
index 95cd10754..94e3e534a 100644
--- a/slither/analyses/data_dependency/data_dependency.py
+++ b/slither/analyses/data_dependency/data_dependency.py
@@ -1,13 +1,14 @@
 """
     Compute the data depenency between all the SSA variables
 """
-from slither.core.declarations import Contract, Function
-from slither.core.declarations.solidity_variables import \
-    SolidityVariableComposed
+from slither.core.declarations import (Contract, Enum, Function,
+                                       SolidityFunction, SolidityVariable,
+                                       SolidityVariableComposed, Structure)
 from slither.slithir.operations import Index, OperationWithLValue
 from slither.slithir.variables import (Constant, LocalIRVariable,
-                                       ReferenceVariable, StateIRVariable,
-                                       TemporaryVariable)
+                                       ReferenceVariable, ReferenceVariableSSA,
+                                       StateIRVariable, TemporaryVariable,
+                                       TemporaryVariableSSA, TupleVariableSSA)
 
 ###################################################################################
 ###################################################################################
@@ -243,7 +244,6 @@ def compute_dependency_function(function):
     function.context[KEY_SSA_UNPROTECTED] = dict()
 
     is_protected = function.is_protected()
-
     for node in function.nodes:
         for ir in node.irs_ssa:
             if isinstance(ir, OperationWithLValue) and ir.lvalue:
@@ -259,10 +259,9 @@ def compute_dependency_function(function):
     function.context[KEY_NON_SSA_UNPROTECTED] = convert_to_non_ssa(function.context[KEY_SSA_UNPROTECTED])
 
 def convert_variable_to_non_ssa(v):
-    if isinstance(v, (LocalIRVariable, StateIRVariable)):
+    if isinstance(v, (LocalIRVariable, StateIRVariable, TemporaryVariableSSA, ReferenceVariableSSA, TupleVariableSSA)):
         return v.non_ssa_version
-    if isinstance(v, (TemporaryVariable, ReferenceVariable)):
-        return next((variable for variable in v.function.slithir_variables if variable.name == v.name))
+    assert isinstance(v, (Constant, SolidityVariable, Contract, Enum, SolidityFunction, Structure, Function))
     return v
 
 def convert_to_non_ssa(data_depencies):
diff --git a/slither/core/cfg/node.py b/slither/core/cfg/node.py
index 7b15937e7..d4c70840e 100644
--- a/slither/core/cfg/node.py
+++ b/slither/core/cfg/node.py
@@ -10,12 +10,13 @@ from slither.core.source_mapping.source_mapping import SourceMapping
 from slither.core.variables.local_variable import LocalVariable
 from slither.core.variables.state_variable import StateVariable
 from slither.core.variables.variable import Variable
+from slither.core.solidity_types import ElementaryType
 from slither.slithir.convert import convert_expression
 from slither.slithir.operations import (Balance, HighLevelCall, Index,
                                         InternalCall, Length, LibraryCall,
                                         LowLevelCall, Member,
                                         OperationWithLValue, Phi, PhiCallback,
-                                        SolidityCall)
+                                        SolidityCall, Return)
 from slither.slithir.variables import (Constant, LocalIRVariable,
                                        ReferenceVariable, StateIRVariable,
                                        TemporaryVariable, TupleVariable)
@@ -424,11 +425,21 @@ class Node(SourceMapping, ChildFunction):
     def is_conditional(self, include_loop=True):
         """
             Check if the node is a conditional node
-            A conditional node is either a IF or a require/assert
+            A conditional node is either a IF or a require/assert or a RETURN bool
         Returns:
             bool: True if the node is a conditional node
         """
-        return self.contains_if(include_loop) or self.contains_require_or_assert()
+        if self.contains_if(include_loop) or self.contains_require_or_assert():
+            return True
+        if self.irs:
+            last_ir = self.irs[-1]
+            if last_ir:
+                if isinstance(last_ir, Return):
+                    for r in last_ir.read:
+                        if r.type == ElementaryType('bool'):
+                            return True
+        return False
+
 
 
     # endregion
@@ -685,6 +696,8 @@ class Node(SourceMapping, ChildFunction):
             elif isinstance(ir, (HighLevelCall)) and not isinstance(ir, LibraryCall):
                 if isinstance(ir.destination.type, Contract):
                     self._high_level_calls.append((ir.destination.type, ir.function))
+                elif ir.destination == SolidityVariable('this'):
+                    self._high_level_calls.append((self.function.contract, ir.function))
                 else:
                     self._high_level_calls.append((ir.destination.type.type, ir.function))
             elif isinstance(ir, LibraryCall):
diff --git a/slither/detectors/reentrancy/reentrancy.py b/slither/detectors/reentrancy/reentrancy.py
index 80b06c26b..527e80273 100644
--- a/slither/detectors/reentrancy/reentrancy.py
+++ b/slither/detectors/reentrancy/reentrancy.py
@@ -59,6 +59,8 @@ class Reentrancy(AbstractDetector):
                 # We can check that the function called is
                 # reentrancy-safe
                 if ir.destination == SolidityVariable('this'):
+                    if isinstance(ir.function, Variable):
+                        continue
                     if not ir.function.all_high_level_calls():
                         if not ir.function.all_low_level_calls():
                             continue
diff --git a/slither/printers/call/call_graph.py b/slither/printers/call/call_graph.py
index a68b7de49..ed5efdfae 100644
--- a/slither/printers/call/call_graph.py
+++ b/slither/printers/call/call_graph.py
@@ -142,6 +142,9 @@ class PrinterCallGraph(AbstractPrinter):
             Args:
                 filename(string)
         """
+        if not filename:
+            filename = "contracts.dot"
+
         if not filename.endswith('.dot'):
             filename += '.dot'
 
diff --git a/slither/printers/inheritance/inheritance_graph.py b/slither/printers/inheritance/inheritance_graph.py
index 9897db4b2..468969002 100644
--- a/slither/printers/inheritance/inheritance_graph.py
+++ b/slither/printers/inheritance/inheritance_graph.py
@@ -171,7 +171,7 @@ class PrinterInheritanceGraph(AbstractPrinter):
                 filename(string)
         """
         if filename == '':
-            filename = 'export'
+            filename = 'contracts.dot'
         if not filename.endswith('.dot'):
             filename += ".dot"
         info = 'Inheritance Graph: ' + filename
diff --git a/slither/slithir/utils/ssa.py b/slither/slithir/utils/ssa.py
index 3b16555bb..d2e983616 100644
--- a/slither/slithir/utils/ssa.py
+++ b/slither/slithir/utils/ssa.py
@@ -1,6 +1,9 @@
 import logging
 
 from slither.core.cfg.node import NodeType
+from slither.core.declarations import (Contract, Enum, Function,
+                                       SolidityFunction, SolidityVariable,
+                                       SolidityVariableComposed, Structure)
 from slither.core.variables.local_variable import LocalVariable
 from slither.core.variables.state_variable import StateVariable
 from slither.slithir.operations import (Assignment, Balance, Binary, Condition,
@@ -14,9 +17,10 @@ from slither.slithir.operations import (Assignment, Balance, Binary, Condition,
                                         Push, Return, Send, SolidityCall,
                                         Transfer, TypeConversion, Unary,
                                         Unpack)
-from slither.slithir.variables import (LocalIRVariable, ReferenceVariable,
+from slither.slithir.variables import (Constant, LocalIRVariable,
+                                       ReferenceVariable, ReferenceVariableSSA,
                                        StateIRVariable, TemporaryVariable,
-                                       TupleVariable)
+                                       TemporaryVariableSSA, TupleVariable, TupleVariableSSA)
 
 logger = logging.getLogger('SSA_Conversion')
 
@@ -164,6 +168,7 @@ def generate_ssa_irs(node, local_variables_instances, all_local_variables_instan
     # They dont need phi function
     temporary_variables_instances = dict()
     reference_variables_instances = dict()
+    tuple_variables_instances = dict()
 
     for ir in node.irs:
         new_ir = copy_ir(ir,
@@ -171,6 +176,7 @@ def generate_ssa_irs(node, local_variables_instances, all_local_variables_instan
                          state_variables_instances,
                          temporary_variables_instances,
                          reference_variables_instances,
+                         tuple_variables_instances,
                          all_local_variables_instances)
 
         update_lvalue(new_ir,
@@ -416,7 +422,81 @@ def add_phi_origins(node, local_variables_definition, state_variables_definition
 ###################################################################################
 ###################################################################################
 
-def copy_ir(ir, local_variables_instances, state_variables_instances, temporary_variables_instances, reference_variables_instances, all_local_variables_instances):
+def get(variable, local_variables_instances, state_variables_instances, temporary_variables_instances, reference_variables_instances, tuple_variables_instances, all_local_variables_instances):
+    # variable can be None
+    # for example, on LowLevelCall, ir.lvalue can be none
+    if variable is None:
+        return None
+    if isinstance(variable, LocalVariable):
+        if variable.name in local_variables_instances:
+            return local_variables_instances[variable.name]
+        new_var = LocalIRVariable(variable)
+        local_variables_instances[variable.name] = new_var
+        all_local_variables_instances[variable.name] = new_var
+        return new_var
+    if isinstance(variable, StateVariable) and variable.canonical_name in state_variables_instances:
+        return state_variables_instances[variable.canonical_name]
+    elif isinstance(variable, ReferenceVariable):
+        if not variable.index in reference_variables_instances:
+            new_variable = ReferenceVariableSSA(variable)
+            if variable.points_to:
+                new_variable.points_to = get(variable.points_to,
+                                             local_variables_instances,
+                                             state_variables_instances,
+                                             temporary_variables_instances,
+                                             reference_variables_instances,
+                                             tuple_variables_instances,
+                                             all_local_variables_instances)
+            new_variable.set_type(variable.type)
+            reference_variables_instances[variable.index] = new_variable
+        return reference_variables_instances[variable.index]
+    elif isinstance(variable, TemporaryVariable):
+        if not variable.index in temporary_variables_instances:
+            new_variable = TemporaryVariableSSA(variable)
+            new_variable.set_type(variable.type)
+            temporary_variables_instances[variable.index] = new_variable
+        return temporary_variables_instances[variable.index]
+    elif isinstance(variable, TupleVariable):
+        if not variable.index in tuple_variables_instances:
+            new_variable = TupleVariableSSA(variable)
+            new_variable.set_type(variable.type)
+            tuple_variables_instances[variable.index] = new_variable
+        return tuple_variables_instances[variable.index]
+    assert isinstance(variable, (Constant,
+                                 SolidityVariable,
+                                 Contract,
+                                 Enum,
+                                 SolidityFunction,
+                                 Structure,
+                                 Function))
+    return variable
+
+def get_variable(ir, f, *instances):
+    variable = f(ir)
+    variable = get(variable, *instances)
+    return variable
+
+def _get_traversal(values, *instances):
+    ret = []
+    for v in values:
+        if isinstance(v, list):
+            v = _get_traversal(v, *instances)
+        else:
+            v = get(v, *instances)
+        ret.append(v)
+    return ret
+
+def get_arguments(ir, *instances):
+    return _get_traversal(ir.arguments, *instances)
+
+def get_rec_values(ir, f, *instances):
+    # Use by InitArray and NewArray
+    # Potential recursive array(s)
+    ori_init_values = f(ir)
+
+    return _get_traversal(ori_init_values, *instances)
+
+def copy_ir(ir, *instances):
     '''
     Args:
         ir (Operation)
@@ -427,213 +507,156 @@ def copy_ir(ir, local_variables_instances, state_variables_instances, temporary_
 
     Note: temporary and reference can be indexed by int, as they dont need phi functions
     '''
-
-    def get(variable):
-        if isinstance(variable, LocalVariable):
-            if variable.name in local_variables_instances:
-                return local_variables_instances[variable.name]
-            new_var = LocalIRVariable(variable)
-            local_variables_instances[variable.name] = new_var
-            all_local_variables_instances[variable.name] = new_var
-            return new_var
-        if isinstance(variable, StateVariable) and variable.canonical_name in state_variables_instances:
-            return state_variables_instances[variable.canonical_name]
-        elif isinstance(variable, ReferenceVariable):
-            if not variable.index in reference_variables_instances:
-                new_variable = ReferenceVariable(variable.node, index=variable.index)
-                if variable.points_to:
-                    new_variable.points_to = get(variable.points_to)
-                new_variable.set_type(variable.type)
-                reference_variables_instances[variable.index] = new_variable
-            return reference_variables_instances[variable.index]
-        elif isinstance(variable, TemporaryVariable):
-            if not variable.index in temporary_variables_instances:
-                new_variable = TemporaryVariable(variable.node, index=variable.index)
-                new_variable.set_type(variable.type)
-                temporary_variables_instances[variable.index] = new_variable
-            return temporary_variables_instances[variable.index]
-        return variable
-
-    def get_variable(ir, f):
-        variable = f(ir)
-        variable = get(variable)
-        return variable
-
-    def get_arguments(ir):
-        arguments = []
-        for arg in ir.arguments:
-            arg = get(arg)
-            arguments.append(arg)
-        return arguments
-
-    def get_rec_values(ir, f):
-        # Use by InitArray and NewArray
-        # Potential recursive array(s)
-        ori_init_values = f(ir)
-
-        def traversal(values):
-            ret = []
-            for v in values:
-                if isinstance(v, list):
-                    v = traversal(v)
-                else:
-                    v = get(v)
-                ret.append(v)
-            return ret
-
-        return traversal(ori_init_values)
-
-
     if isinstance(ir, Assignment):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        rvalue = get_variable(ir, lambda x: ir.rvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        rvalue = get_variable(ir, lambda x: x.rvalue, *instances)
         variable_return_type = ir.variable_return_type
         return Assignment(lvalue, rvalue, variable_return_type)
     elif isinstance(ir, Balance):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        value = get_variable(ir, lambda x: ir.value)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        value = get_variable(ir, lambda x: x.value, *instances)
         return Balance(value, lvalue)
     elif isinstance(ir, Binary):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        variable_left = get_variable(ir, lambda x: ir.variable_left)
-        variable_right = get_variable(ir, lambda x: ir.variable_right)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        variable_left = get_variable(ir, lambda x: x.variable_left, *instances)
+        variable_right = get_variable(ir, lambda x: x.variable_right, *instances)
         operation_type = ir.type
         return Binary(lvalue, variable_left, variable_right, operation_type)
     elif isinstance(ir, Condition):
-        val = get_variable(ir, lambda x: ir.value)
+        val = get_variable(ir, lambda x: x.value, *instances)
         return Condition(val)
     elif isinstance(ir, Delete):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        variable = get_variable(ir, lambda x: ir.variable)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        variable = get_variable(ir, lambda x: x.variable, *instances)
         return Delete(lvalue, variable)
     elif isinstance(ir, EventCall):
         name = ir.name
         return EventCall(name)
     elif isinstance(ir, HighLevelCall): # include LibraryCall
-        destination = get_variable(ir, lambda x: ir.destination)
+        destination = get_variable(ir, lambda x: x.destination, *instances)
         function_name = ir.function_name
         nbr_arguments = ir.nbr_arguments
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         type_call = ir.type_call
         if isinstance(ir, LibraryCall):
             new_ir = LibraryCall(destination, function_name, nbr_arguments, lvalue, type_call)
         else:
             new_ir = HighLevelCall(destination, function_name, nbr_arguments, lvalue, type_call)
         new_ir.call_id = ir.call_id
-        new_ir.call_value = get_variable(ir, lambda x: ir.call_value)
-        new_ir.call_gas = get_variable(ir, lambda x: ir.call_gas)
-        new_ir.arguments = get_arguments(ir)
+        new_ir.call_value = get_variable(ir, lambda x: x.call_value, *instances)
+        new_ir.call_gas = get_variable(ir, lambda x: x.call_gas, *instances)
+        new_ir.arguments = get_arguments(ir, *instances)
         new_ir.function = ir.function
         return new_ir
     elif isinstance(ir, Index):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        variable_left = get_variable(ir, lambda x: ir.variable_left)
-        variable_right = get_variable(ir, lambda x: ir.variable_right)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        variable_left = get_variable(ir, lambda x: x.variable_left, *instances)
+        variable_right = get_variable(ir, lambda x: x.variable_right, *instances)
         index_type = ir.index_type
         return Index(lvalue, variable_left, variable_right, index_type)
     elif isinstance(ir, InitArray):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        init_values = get_rec_values(ir, lambda x: ir.init_values)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        init_values = get_rec_values(ir, lambda x: x.init_values, *instances)
         return InitArray(init_values, lvalue)
     elif isinstance(ir, InternalCall):
         function = ir.function
         nbr_arguments = ir.nbr_arguments
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         type_call = ir.type_call
         new_ir = InternalCall(function, nbr_arguments, lvalue, type_call)
-        new_ir.arguments = get_arguments(ir)
+        new_ir.arguments = get_arguments(ir, *instances)
         return new_ir
     elif isinstance(ir, InternalDynamicCall):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        function = ir.function
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        function = get_variable(ir, lambda x: x.function, *instances)
         function_type = ir.function_type
         new_ir = InternalDynamicCall(lvalue, function, function_type)
-        new_ir.arguments = get_arguments(ir)
+        new_ir.arguments = get_arguments(ir, *instances)
         return new_ir
     elif isinstance(ir, LowLevelCall):
-        destination = get_variable(ir, lambda x: x.destination)
+        destination = get_variable(ir, lambda x: x.destination, *instances)
         function_name = ir.function_name
         nbr_arguments = ir.nbr_arguments
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         type_call = ir.type_call
         new_ir = LowLevelCall(destination, function_name, nbr_arguments, lvalue, type_call)
         new_ir.call_id = ir.call_id
-        new_ir.call_value = get_variable(ir, lambda x: ir.call_value)
-        new_ir.call_gas = get_variable(ir, lambda x: ir.call_gas)
-        new_ir.arguments = get_arguments(ir)
+        new_ir.call_value = get_variable(ir, lambda x: x.call_value, *instances)
+        new_ir.call_gas = get_variable(ir, lambda x: x.call_gas, *instances)
+        new_ir.arguments = get_arguments(ir, *instances)
         return new_ir
     elif isinstance(ir, Member):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        variable_left = get_variable(ir, lambda x: ir.variable_left)
-        variable_right = get_variable(ir, lambda x: ir.variable_right)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        variable_left = get_variable(ir, lambda x: x.variable_left, *instances)
+        variable_right = get_variable(ir, lambda x: x.variable_right, *instances)
         return Member(variable_left, variable_right, lvalue)
     elif isinstance(ir, NewArray):
         depth = ir.depth
         array_type = ir.array_type
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         new_ir = NewArray(depth, array_type, lvalue)
-        new_ir.arguments = get_rec_values(ir, lambda x: ir.arguments)
+        new_ir.arguments = get_rec_values(ir, lambda x: x.arguments, *instances)
         return new_ir
     elif isinstance(ir, NewElementaryType):
         new_type = ir.type
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         new_ir = NewElementaryType(new_type, lvalue)
-        new_ir.arguments = get_arguments(ir)
+        new_ir.arguments = get_arguments(ir, *instances)
         return new_ir
     elif isinstance(ir, NewContract):
         contract_name = ir.contract_name
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         new_ir = NewContract(contract_name, lvalue)
-        new_ir.arguments = get_arguments(ir)
+        new_ir.arguments = get_arguments(ir, *instances)
         return new_ir
     elif isinstance(ir, NewStructure):
         structure = ir.structure
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         new_ir = NewStructure(structure, lvalue)
-        new_ir.arguments = get_arguments(ir)
+        new_ir.arguments = get_arguments(ir, *instances)
         return new_ir
     elif isinstance(ir, Push):
-        array = get_variable(ir, lambda x: ir.array)
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        array = get_variable(ir, lambda x: x.array, *instances)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         return Push(array, lvalue)
     elif isinstance(ir, Return):
-        value = [get_variable(x, lambda y: y) for x in ir.values]
-        return Return(value)
+        values = get_rec_values(ir, lambda x: x.values, *instances)
+        return Return(values)
     elif isinstance(ir, Send):
-        destination = get_variable(ir, lambda x: ir.destination)
-        value = get_variable(ir, lambda x: ir.call_value)
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        destination = get_variable(ir, lambda x: x.destination, *instances)
+        value = get_variable(ir, lambda x: x.call_value, *instances)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         return Send(destination, value, lvalue)
     elif isinstance(ir, SolidityCall):
         function = ir.function
         nbr_arguments = ir.nbr_arguments
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
         type_call = ir.type_call
         new_ir = SolidityCall(function, nbr_arguments, lvalue, type_call)
-        new_ir.arguments = get_arguments(ir)
+        new_ir.arguments = get_arguments(ir, *instances)
         return new_ir
     elif isinstance(ir, Transfer):
-        destination = get_variable(ir, lambda x: ir.destination)
-        value = get_variable(ir, lambda x: ir.call_value)
+        destination = get_variable(ir, lambda x: x.destination, *instances)
+        value = get_variable(ir, lambda x: x.call_value, *instances)
         return Transfer(destination, value)
     elif isinstance(ir, TypeConversion):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        variable = get_variable(ir, lambda x: ir.variable)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        variable = get_variable(ir, lambda x: x.variable, *instances)
         variable_type = ir.type
         return TypeConversion(lvalue, variable, variable_type)
     elif isinstance(ir, Unary):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        rvalue = get_variable(ir, lambda x: ir.rvalue)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        rvalue = get_variable(ir, lambda x: x.rvalue, *instances)
         operation_type = ir.type
         return Unary(lvalue, rvalue, operation_type)
     elif isinstance(ir, Unpack):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        tuple_var = ir.tuple
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        tuple_var = get_variable(ir, lambda x: x.tuple, *instances)
         idx = ir.index
         return Unpack(lvalue, tuple_var, idx)
     elif isinstance(ir, Length):
-        lvalue = get_variable(ir, lambda x: ir.lvalue)
-        value = get_variable(ir, lambda x: ir.value)
+        lvalue = get_variable(ir, lambda x: x.lvalue, *instances)
+        value = get_variable(ir, lambda x: x.value, *instances)
         return Length(value, lvalue)
 
 
diff --git a/slither/slithir/variables/__init__.py b/slither/slithir/variables/__init__.py
index 416d90108..624287318 100644
--- a/slither/slithir/variables/__init__.py
+++ b/slither/slithir/variables/__init__.py
@@ -1,6 +1,9 @@
 from .constant import Constant
 from .reference import ReferenceVariable
+from .reference_ssa import ReferenceVariableSSA
 from .temporary import TemporaryVariable
+from .temporary_ssa import TemporaryVariableSSA
 from .tuple import TupleVariable
+from .tuple_ssa import TupleVariableSSA
 from .local_variable import LocalIRVariable
 from .state_variable import StateIRVariable
diff --git a/slither/slithir/variables/reference_ssa.py b/slither/slithir/variables/reference_ssa.py
new file mode 100644
index 000000000..b8c10993c
--- /dev/null
+++ b/slither/slithir/variables/reference_ssa.py
@@ -0,0 +1,18 @@
+'''
+    This class is used for the SSA version of slithIR
+    It is similar to the non-SSA version of slithIR
+    as the ReferenceVariable are in SSA form in both version
+'''
+from .reference import ReferenceVariable
+from .variable import SlithIRVariable
+
+class ReferenceVariableSSA(ReferenceVariable):
+
+    def __init__(self, reference):
+        super(ReferenceVariableSSA, self).__init__(reference.node, reference.index)
+
+        self._non_ssa_version = reference
+
+    @property
+    def non_ssa_version(self):
+        return self._non_ssa_version
diff --git a/slither/slithir/variables/temporary_ssa.py b/slither/slithir/variables/temporary_ssa.py
new file mode 100644
index 000000000..b36e73419
--- /dev/null
+++ b/slither/slithir/variables/temporary_ssa.py
@@ -0,0 +1,20 @@
+'''
+    This class is used for the SSA version of slithIR
+    It is similar to the non-SSA version of slithIR
+    as the TemporaryVariable are in SSA form in both version
+'''
+from .temporary import TemporaryVariable
+from .variable import SlithIRVariable
+
+class TemporaryVariableSSA(TemporaryVariable):
+
+    def __init__(self, temporary):
+        super(TemporaryVariableSSA, self).__init__(temporary.node, temporary.index)
+
+        self._non_ssa_version = temporary
+
+
+    @property
+    def non_ssa_version(self):
+        return self._non_ssa_version
+
diff --git a/slither/slithir/variables/tuple.py b/slither/slithir/variables/tuple.py
index d95c48e20..bfff48586 100644
--- a/slither/slithir/variables/tuple.py
+++ b/slither/slithir/variables/tuple.py
@@ -1,15 +1,21 @@
 from .variable import SlithIRVariable
 from slither.core.variables.variable import Variable
+from slither.core.children.child_node import ChildNode
 
 from slither.core.solidity_types.type import Type
-class TupleVariable(SlithIRVariable):
+class TupleVariable(ChildNode, SlithIRVariable):
 
     COUNTER = 0
 
-    def __init__(self):
+    def __init__(self, node, index=None):
         super(TupleVariable, self).__init__()
-        self._index = TupleVariable.COUNTER
-        TupleVariable.COUNTER += 1
+        if index is None:
+            self._index = TupleVariable.COUNTER
+            TupleVariable.COUNTER += 1
+        else:
+            self._index = index
+
+        self._node = node
 
     @property
     def index(self):
diff --git a/slither/slithir/variables/tuple_ssa.py b/slither/slithir/variables/tuple_ssa.py
new file mode 100644
index 000000000..04c050260
--- /dev/null
+++ b/slither/slithir/variables/tuple_ssa.py
@@ -0,0 +1,20 @@
+'''
+    This class is used for the SSA version of slithIR
+    It is similar to the non-SSA version of slithIR
+    as the TupleVariable are in SSA form in both version
+'''
+from .tuple import TupleVariable
+from .variable import SlithIRVariable
+
+class TupleVariableSSA(TupleVariable):
+
+    def __init__(self, t):
+        super(TupleVariableSSA, self).__init__(t.node, t.index)
+
+        self._non_ssa_version = t
+
+
+    @property
+    def non_ssa_version(self):
+        return self._non_ssa_version
+
diff --git a/slither/solc_parsing/solidity_types/type_parsing.py b/slither/solc_parsing/solidity_types/type_parsing.py
index 1a26612dd..2b5057dda 100644
--- a/slither/solc_parsing/solidity_types/type_parsing.py
+++ b/slither/solc_parsing/solidity_types/type_parsing.py
@@ -160,7 +160,10 @@ def parse_type(t, caller_context):
     elif t[key] == 'UserDefinedTypeName':
         if is_compact_ast:
             return _find_from_type_name(t['typeDescriptions']['typeString'], contract, contracts, structures, enums)
-        return _find_from_type_name(t['attributes'][key], contract, contracts, structures, enums)
+
+        # Determine if we have a type node (otherwise we use the name node, as some older solc did not have 'type').
+        type_name_key = 'type' if 'type' in t['attributes'] else key
+        return _find_from_type_name(t['attributes'][type_name_key], contract, contracts, structures, enums)
 
     elif t[key] == 'ArrayTypeName':
         length = None
diff --git a/slither/visitors/slithir/expression_to_slithir.py b/slither/visitors/slithir/expression_to_slithir.py
index fd191df56..a1f682f88 100644
--- a/slither/visitors/slithir/expression_to_slithir.py
+++ b/slither/visitors/slithir/expression_to_slithir.py
@@ -128,7 +128,7 @@ class ExpressionToSlithIR(ExpressionVisitor):
 
             # If tuple
             if expression.type_call.startswith('tuple(') and expression.type_call != 'tuple()':
-                val = TupleVariable()
+                val = TupleVariable(self._node)
             else:
                 val = TemporaryVariable(self._node)
             internal_call = InternalCall(called, len(args), val, expression.type_call)
@@ -139,7 +139,7 @@ class ExpressionToSlithIR(ExpressionVisitor):
 
             # If tuple
             if expression.type_call.startswith('tuple(') and expression.type_call != 'tuple()':
-                val = TupleVariable()
+                val = TupleVariable(self._node)
             else:
                 val = TemporaryVariable(self._node)