diff --git a/examples/discover_writes.py b/examples/discover_writes.py
deleted file mode 100644
index 50e7378c..00000000
--- a/examples/discover_writes.py
+++ /dev/null
@@ -1,91 +0,0 @@
-from mythril.ether import util
-from mythril.rpc.client import EthJsonRpc
-from mythril.ether.contractstorage import get_persistent_storage
-from mythril.disassembler.disassembly import Disassembly
-from ethereum.abi import encode_abi
-import re
-import os
-
-
-# Discover contract functions that write the sender address, or an address passed as an argument, to storage.
-# Needs testrpc running on port 8546
-
-# testrpc --port 8546 --gasLimit 0xFFFFFF --account 0x0b6f3fd29ca0e570faf9d0bb8945858b9c337cd2a2ff89d65013eec412a4a811,500000000000000000000 --account 0x2194ac1cd3b9ca6cccc1a90aa2c6f944994b80bb50c82b973adce7f288734d5c,500000000000000000000
-
-
-addr_knupper= "0xe2beffc4bc7ebb9eae43d59d2b555749d9ce7c54"
-addr_schnupper = "0xadc2f8617191ff60a36c3c136170cc69c03e64cd"
-
-contract_storage = get_persistent_storage(os.path.join(os.path.expanduser('~'), ".mythril"))
-testrpc = EthJsonRpc("localhost", 8546)
-
-testargs1 = [
-    ([], []),
-    (['address'], [addr_schnupper]),
-    (['address', 'uint256'], [addr_schnupper, 1 ]), 
-    (['address', 'uint256', 'uint256'], [addr_schnupper, 1, 1]), 
-    (['address[]'], [[addr_schnupper]]),
-    (['address[]', 'uint256'], [[addr_schnupper], 1 ]),     
-    (['address[]', 'uint256', 'uint256'], [[addr_schnupper], 1, 1]), 
-]
-
-
-def testCase(contract_addr, function_selector, arg_types, args):
-
-    if re.match(r'^UNK_0x', function_selector):
-        args = encode_abi(['address'], [addr_schnupper])
-        data= function_selector[4:] + args.hex()
-    else:
-        data = util.encode_calldata(function_selector, arg_types, args)
-
-    tx = testrpc.eth_sendTransaction(to_address=contract_addr, from_address=addr_schnupper, gas=5000000, value=0, data=data)
-
-    trace = testrpc.traceTransaction(tx)
-
-    if trace:
-        for t in trace['structLogs']:
-            if t['op'] == 'SSTORE':
-                if addr_schnupper[2:] in t['stack'][-2]:
-                    return True
-
-    return False
-
-
-def testDynamic(contract_hash, contract, addresses, balances):
-
-    ret = testrpc.eth_sendTransaction(from_address=addr_knupper, gas=5000000, value=0, data=contract.creation_code)
-    receipt = testrpc.eth_getTransactionReceipt(ret)
-    contract_addr = receipt['contractAddress']
-
-    try:
-        disas = Disassembly(contract.code)
-    except:
-        return
-        
-    found = False
-
-    for function_selector in disas.func_to_addr:
-
-        try:
-            for t in testargs1:
-                if(testCase(contract_addr, function_selector, t[0], t[1])):
-                    print("Possible write!")
-                    print("Contract hash: " + contract_hash)
-                    print("Selector: " + function_selector)
-                    print("Input data: " + str(t[1]))
-
-                    for i in range(0, len(addresses)):
-                        print("Address: " + addresses[i] + ", balance: " + str(balances[i]))
-
-                    found = True
-                    break
-
-            if found:
-                break
-        except:
-            break
-
-
-print("Searching " +str(len(list(contract_storage.contracts))) + " contracts...")
-
-contract_storage.search("code#PUSH#", testDynamic) # Returns all contracts
diff --git a/examples/find-fallback-dcl.py b/examples/find-fallback-dcl.py
deleted file mode 100644
index fc242eee..00000000
--- a/examples/find-fallback-dcl.py
+++ /dev/null
@@ -1,72 +0,0 @@
-from mythril.ether import evm
-from mythril.ether.contractstorage import get_persistent_storage
-from mythril.disassembler.disassembly import Disassembly
-from mythril.rpc.client import EthJsonRpc
-from mythril.disassembler.callgraph import generate_callgraph
-import os
-
-
-contract_storage = get_persistent_storage()
-contract_keys = list(contract_storage.contracts)
-homestead = EthJsonRpc()
-
-# Iterate over all contracts in the database
-
-for k in contract_keys:
-
-    contract = contract_storage.contracts[k]
-
-    # Run each contract in the PyEthereum EVM trace to check whether DELEGATECALL is reached
-    # To execute the fallback function, we don't provide any input data
-
-    ret = evm.trace(contract.code)
-
-    if 'DELEGATECALL' in ret:
-
-        print("DELEGATECALL in fallback function: Contract 0x" + k.hex() + " deployed at: ")
-
-        instance_list = contract_storage.instance_lists[k]
-
-        for i in range(1, len(instance_list.addresses)):
-            print("Address: " + instance_list.addresses[i] + ", balance: " + str(instance_list.balances[i]))
-
-        # contract.get_xrefs() should contain the delegateCall() target (library contract)
-
-        print("Referenced contracts:")
-
-        xrefs = contract.get_xrefs()
-
-        print ("\n".join(xrefs))
-
-        '''
-        from here on are many different options!
-
-        In this example, we'll only check one of the refernced contracts contains the initWallet() function
-        If it does, we save the disassembly and callgraph for further analysis
-        
-        '''
- 
-        for xref in xrefs:
-            code = homestead.eth_getCode(xref)
-
-            disassembly = Disassembly(code)
-
-            if contract.matches_expression("func#initWallet(address[],uint256,uint256)#"):
-                print ("initWallet() in referenced library contract: " + xref)
-
-                # Save list of contracts that forward calls to this library contract
-
-                cwd = os.getcwd()
-
-                with open("contracts_calling_" + xref + ".txt", "w") as f:
-                    addresses = contract_storage.instance_lists[k].addresses
-
-                    f.write("\n".join(addresses))
-
-                easm = disassembly.get_easm()
-
-                with open("library_" + xref + ".easm", "w") as f:
-                    f.write(easm)
-
-                generate_callgraph(disassembly, os.path.join(cwd, "library_" + xref))
-
diff --git a/examples/walletlibrary.sol b/examples/walletlibrary.sol
deleted file mode 100644
index f446f766..00000000
--- a/examples/walletlibrary.sol
+++ /dev/null
@@ -1,464 +0,0 @@
-//sol Wallet
-// Multi-sig, daily-limited account proxy/wallet.
-// @authors:
-// Gav Wood <g@ethdev.com>
-// inheritable "property" contract that enables methods to be protected by requiring the acquiescence of either a
-// single, or, crucially, each of a number of, designated owners.
-// usage:
-// use modifiers onlyowner (just own owned) or onlymanyowners(hash), whereby the same hash must be provided by
-// some number (specified in constructor) of the set of owners (specified in the constructor, modifiable) before the
-// interior is executed.
-
-pragma solidity ^0.4.9;
-
-contract WalletEvents {
-  // EVENTS
-
-  // this contract only has six types of events: it can accept a confirmation, in which case
-  // we record owner and operation (hash) alongside it.
-  event Confirmation(address owner, bytes32 operation);
-  event Revoke(address owner, bytes32 operation);
-
-  // some others are in the case of an owner changing.
-  event OwnerChanged(address oldOwner, address newOwner);
-  event OwnerAdded(address newOwner);
-  event OwnerRemoved(address oldOwner);
-
-  // the last one is emitted if the required signatures change
-  event RequirementChanged(uint newRequirement);
-
-  // Funds has arrived into the wallet (record how much).
-  event Deposit(address _from, uint value);
-  // Single transaction going out of the wallet (record who signed for it, how much, and to whom it's going).
-  event SingleTransact(address owner, uint value, address to, bytes data, address created);
-  // Multi-sig transaction going out of the wallet (record who signed for it last, the operation hash, how much, and to whom it's going).
-  event MultiTransact(address owner, bytes32 operation, uint value, address to, bytes data, address created);
-  // Confirmation still needed for a transaction.
-  event ConfirmationNeeded(bytes32 operation, address initiator, uint value, address to, bytes data);
-}
-
-contract WalletAbi {
-  // Revokes a prior confirmation of the given operation
-  function revoke(bytes32 _operation) external;
-
-  // Replaces an owner `_from` with another `_to`.
-  function changeOwner(address _from, address _to) external;
-
-  function addOwner(address _owner) external;
-
-  function removeOwner(address _owner) external;
-
-  function changeRequirement(uint _newRequired) external;
-
-  function isOwner(address _addr) constant returns (bool);
-
-  function hasConfirmed(bytes32 _operation, address _owner) external constant returns (bool);
-
-  // (re)sets the daily limit. needs many of the owners to confirm. doesn't alter the amount already spent today.
-  function setDailyLimit(uint _newLimit) external;
-
-  function execute(address _to, uint _value, bytes _data) external returns (bytes32 o_hash);
-  function confirm(bytes32 _h) returns (bool o_success);
-}
-
-contract WalletLibrary is WalletEvents {
-  // TYPES
-
-  // struct for the status of a pending operation.
-  struct PendingState {
-    uint yetNeeded;
-    uint ownersDone;
-    uint index;
-  }
-
-  // Transaction structure to remember details of transaction lest it need be saved for a later call.
-  struct Transaction {
-    address to;
-    uint value;
-    bytes data;
-  }
-
-  // MODIFIERS
-
-  // simple single-sig function modifier.
-  modifier onlyowner {
-    if (isOwner(msg.sender))
-      _;
-  }
-  // multi-sig function modifier: the operation must have an intrinsic hash in order
-  // that later attempts can be realised as the same underlying operation and
-  // thus count as confirmations.
-  modifier onlymanyowners(bytes32 _operation) {
-    if (confirmAndCheck(_operation))
-      _;
-  }
-
-  // METHODS
-
-  // gets called when no other function matches
-  function() payable {
-    // just being sent some cash?
-    if (msg.value > 0)
-      Deposit(msg.sender, msg.value);
-  }
-
-  // constructor is given number of sigs required to do protected "onlymanyowners" transactions
-  // as well as the selection of addresses capable of confirming them.
-  function initMultiowned(address[] _owners, uint _required) only_uninitialized {
-    m_numOwners = _owners.length + 1;
-    m_owners[1] = uint(msg.sender);
-    m_ownerIndex[uint(msg.sender)] = 1;
-    for (uint i = 0; i < _owners.length; ++i)
-    {
-      m_owners[2 + i] = uint(_owners[i]);
-      m_ownerIndex[uint(_owners[i])] = 2 + i;
-    }
-    m_required = _required;
-  }
-
-  // Revokes a prior confirmation of the given operation
-  function revoke(bytes32 _operation) external {
-    uint ownerIndex = m_ownerIndex[uint(msg.sender)];
-    // make sure they're an owner
-    if (ownerIndex == 0) return;
-    uint ownerIndexBit = 2**ownerIndex;
-    var pending = m_pending[_operation];
-    if (pending.ownersDone & ownerIndexBit > 0) {
-      pending.yetNeeded++;
-      pending.ownersDone -= ownerIndexBit;
-      Revoke(msg.sender, _operation);
-    }
-  }
-
-  // Replaces an owner `_from` with another `_to`.
-  function changeOwner(address _from, address _to) onlymanyowners(sha3(msg.data)) external {
-    if (isOwner(_to)) return;
-    uint ownerIndex = m_ownerIndex[uint(_from)];
-    if (ownerIndex == 0) return;
-
-    clearPending();
-    m_owners[ownerIndex] = uint(_to);
-    m_ownerIndex[uint(_from)] = 0;
-    m_ownerIndex[uint(_to)] = ownerIndex;
-    OwnerChanged(_from, _to);
-  }
-
-  function addOwner(address _owner) onlymanyowners(sha3(msg.data)) external {
-    if (isOwner(_owner)) return;
-
-    clearPending();
-    if (m_numOwners >= c_maxOwners)
-      reorganizeOwners();
-    if (m_numOwners >= c_maxOwners)
-      return;
-    m_numOwners++;
-    m_owners[m_numOwners] = uint(_owner);
-    m_ownerIndex[uint(_owner)] = m_numOwners;
-    OwnerAdded(_owner);
-  }
-
-  function removeOwner(address _owner) onlymanyowners(sha3(msg.data)) external {
-    uint ownerIndex = m_ownerIndex[uint(_owner)];
-    if (ownerIndex == 0) return;
-    if (m_required > m_numOwners - 1) return;
-
-    m_owners[ownerIndex] = 0;
-    m_ownerIndex[uint(_owner)] = 0;
-    clearPending();
-    reorganizeOwners(); //make sure m_numOwner is equal to the number of owners and always points to the optimal free slot
-    OwnerRemoved(_owner);
-  }
-
-  function changeRequirement(uint _newRequired) onlymanyowners(sha3(msg.data)) external {
-    if (_newRequired > m_numOwners) return;
-    m_required = _newRequired;
-    clearPending();
-    RequirementChanged(_newRequired);
-  }
-
-  // Gets an owner by 0-indexed position (using numOwners as the count)
-  function getOwner(uint ownerIndex) external constant returns (address) {
-    return address(m_owners[ownerIndex + 1]);
-  }
-
-  function isOwner(address _addr) constant returns (bool) {
-    return m_ownerIndex[uint(_addr)] > 0;
-  }
-
-  function hasConfirmed(bytes32 _operation, address _owner) external constant returns (bool) {
-    var pending = m_pending[_operation];
-    uint ownerIndex = m_ownerIndex[uint(_owner)];
-
-    // make sure they're an owner
-    if (ownerIndex == 0) return false;
-
-    // determine the bit to set for this owner.
-    uint ownerIndexBit = 2**ownerIndex;
-    return !(pending.ownersDone & ownerIndexBit == 0);
-  }
-
-  // constructor - stores initial daily limit and records the present day's index.
-  function initDaylimit(uint _limit) only_uninitialized {
-    m_dailyLimit = _limit;
-    m_lastDay = today();
-  }
-  // (re)sets the daily limit. needs many of the owners to confirm. doesn't alter the amount already spent today.
-  function setDailyLimit(uint _newLimit) onlymanyowners(sha3(msg.data)) external {
-    m_dailyLimit = _newLimit;
-  }
-  // resets the amount already spent today. needs many of the owners to confirm.
-  function resetSpentToday() onlymanyowners(sha3(msg.data)) external {
-    m_spentToday = 0;
-  }
-
-  // throw unless the contract is not yet initialized.
-  modifier only_uninitialized { if (m_numOwners > 0) throw; _; }
-
-  // constructor - just pass on the owner array to the multiowned and
-  // the limit to daylimit
-  function initWallet(address[] _owners, uint _required, uint _daylimit) only_uninitialized {
-    initDaylimit(_daylimit);
-    initMultiowned(_owners, _required);
-  }
-
-  // kills the contract sending everything to `_to`.
-  function kill(address _to) onlymanyowners(sha3(msg.data)) external {
-    suicide(_to);
-  }
-
-  // Outside-visible transact entry point. Executes transaction immediately if below daily spend limit.
-  // If not, goes into multisig process. We provide a hash on return to allow the sender to provide
-  // shortcuts for the other confirmations (allowing them to avoid replicating the _to, _value
-  // and _data arguments). They still get the option of using them if they want, anyways.
-  function execute(address _to, uint _value, bytes _data) external onlyowner returns (bytes32 o_hash) {
-    // first, take the opportunity to check that we're under the daily limit.
-    if ((_data.length == 0 && underLimit(_value)) || m_required == 1) {
-      // yes - just execute the call.
-      address created;
-      if (_to == 0) {
-        created = create(_value, _data);
-      } else {
-        if (!_to.call.value(_value)(_data))
-          throw;
-      }
-      SingleTransact(msg.sender, _value, _to, _data, created);
-    } else {
-      // determine our operation hash.
-      o_hash = sha3(msg.data, block.number);
-      // store if it's new
-      if (m_txs[o_hash].to == 0 && m_txs[o_hash].value == 0 && m_txs[o_hash].data.length == 0) {
-        m_txs[o_hash].to = _to;
-        m_txs[o_hash].value = _value;
-        m_txs[o_hash].data = _data;
-      }
-      if (!confirm(o_hash)) {
-        ConfirmationNeeded(o_hash, msg.sender, _value, _to, _data);
-      }
-    }
-  }
-
-  function create(uint _value, bytes _code) internal returns (address o_addr) {
-    assembly {
-      o_addr := create(_value, add(_code, 0x20), mload(_code))
-      jumpi(invalidJumpLabel, iszero(extcodesize(o_addr)))
-    }
-  }
-
-  // confirm a transaction through just the hash. we use the previous transactions map, m_txs, in order
-  // to determine the body of the transaction from the hash provided.
-  function confirm(bytes32 _h) onlymanyowners(_h) returns (bool o_success) {
-    if (m_txs[_h].to != 0 || m_txs[_h].value != 0 || m_txs[_h].data.length != 0) {
-      address created;
-      if (m_txs[_h].to == 0) {
-        created = create(m_txs[_h].value, m_txs[_h].data);
-      } else {
-        if (!m_txs[_h].to.call.value(m_txs[_h].value)(m_txs[_h].data))
-          throw;
-      }
-
-      MultiTransact(msg.sender, _h, m_txs[_h].value, m_txs[_h].to, m_txs[_h].data, created);
-      delete m_txs[_h];
-      return true;
-    }
-  }
-
-  // INTERNAL METHODS
-
-  function confirmAndCheck(bytes32 _operation) internal returns (bool) {
-    // determine what index the present sender is:
-    uint ownerIndex = m_ownerIndex[uint(msg.sender)];
-    // make sure they're an owner
-    if (ownerIndex == 0) return;
-
-    var pending = m_pending[_operation];
-    // if we're not yet working on this operation, switch over and reset the confirmation status.
-    if (pending.yetNeeded == 0) {
-      // reset count of confirmations needed.
-      pending.yetNeeded = m_required;
-      // reset which owners have confirmed (none) - set our bitmap to 0.
-      pending.ownersDone = 0;
-      pending.index = m_pendingIndex.length++;
-      m_pendingIndex[pending.index] = _operation;
-    }
-    // determine the bit to set for this owner.
-    uint ownerIndexBit = 2**ownerIndex;
-    // make sure we (the message sender) haven't confirmed this operation previously.
-    if (pending.ownersDone & ownerIndexBit == 0) {
-      Confirmation(msg.sender, _operation);
-      // ok - check if count is enough to go ahead.
-      if (pending.yetNeeded <= 1) {
-        // enough confirmations: reset and run interior.
-        delete m_pendingIndex[m_pending[_operation].index];
-        delete m_pending[_operation];
-        return true;
-      }
-      else
-      {
-        // not enough: record that this owner in particular confirmed.
-        pending.yetNeeded--;
-        pending.ownersDone |= ownerIndexBit;
-      }
-    }
-  }
-
-  function reorganizeOwners() private {
-    uint free = 1;
-    while (free < m_numOwners)
-    {
-      while (free < m_numOwners && m_owners[free] != 0) free++;
-      while (m_numOwners > 1 && m_owners[m_numOwners] == 0) m_numOwners--;
-      if (free < m_numOwners && m_owners[m_numOwners] != 0 && m_owners[free] == 0)
-      {
-        m_owners[free] = m_owners[m_numOwners];
-        m_ownerIndex[m_owners[free]] = free;
-        m_owners[m_numOwners] = 0;
-      }
-    }
-  }
-
-  // checks to see if there is at least `_value` left from the daily limit today. if there is, subtracts it and
-  // returns true. otherwise just returns false.
-  function underLimit(uint _value) internal onlyowner returns (bool) {
-    // reset the spend limit if we're on a different day to last time.
-    if (today() > m_lastDay) {
-      m_spentToday = 0;
-      m_lastDay = today();
-    }
-    // check to see if there's enough left - if so, subtract and return true.
-    // overflow protection                    // dailyLimit check
-    if (m_spentToday + _value >= m_spentToday && m_spentToday + _value <= m_dailyLimit) {
-      m_spentToday += _value;
-      return true;
-    }
-    return false;
-  }
-
-  // determines today's index.
-  function today() private constant returns (uint) { return now / 1 days; }
-
-  function clearPending() internal {
-    uint length = m_pendingIndex.length;
-
-    for (uint i = 0; i < length; ++i) {
-      delete m_txs[m_pendingIndex[i]];
-
-      if (m_pendingIndex[i] != 0)
-        delete m_pending[m_pendingIndex[i]];
-    }
-
-    delete m_pendingIndex;
-  }
-
-  // FIELDS
-  address constant _walletLibrary = 0xcafecafecafecafecafecafecafecafecafecafe;
-
-  // the number of owners that must confirm the same operation before it is run.
-  uint public m_required;
-  // pointer used to find a free slot in m_owners
-  uint public m_numOwners;
-
-  uint public m_dailyLimit;
-  uint public m_spentToday;
-  uint public m_lastDay;
-
-  // list of owners
-  uint[256] m_owners;
-
-  uint constant c_maxOwners = 250;
-  // index on the list of owners to allow reverse lookup
-  mapping(uint => uint) m_ownerIndex;
-  // the ongoing operations.
-  mapping(bytes32 => PendingState) m_pending;
-  bytes32[] m_pendingIndex;
-
-  // pending transactions we have at present.
-  mapping (bytes32 => Transaction) m_txs;
-}
-
-contract Wallet is WalletEvents {
-
-  // WALLET CONSTRUCTOR
-  //   calls the `initWallet` method of the Library in this context
-  function Wallet(address[] _owners, uint _required, uint _daylimit) {
-    // Signature of the Wallet Library's init function
-    bytes4 sig = bytes4(sha3("initWallet(address[],uint256,uint256)"));
-    address target = _walletLibrary;
-
-    // Compute the size of the call data : arrays has 2
-    // 32bytes for offset and length, plus 32bytes per element ;
-    // plus 2 32bytes for each uint
-    uint argarraysize = (2 + _owners.length);
-    uint argsize = (2 + argarraysize) * 32;
-
-    assembly {
-      // Add the signature first to memory
-      mstore(0x0, sig)
-      // Add the call data, which is at the end of the
-      // code
-      codecopy(0x4,  sub(codesize, argsize), argsize)
-      // Delegate call to the library
-      delegatecall(sub(gas, 10000), target, 0x0, add(argsize, 0x4), 0x0, 0x0)
-    }
-  }
-
-  // METHODS
-
-  // gets called when no other function matches
-  function() payable {
-    // just being sent some cash?
-    if (msg.value > 0)
-      Deposit(msg.sender, msg.value);
-    else if (msg.data.length > 0)
-      _walletLibrary.delegatecall(msg.data);
-  }
-
-  // Gets an owner by 0-indexed position (using numOwners as the count)
-  function getOwner(uint ownerIndex) constant returns (address) {
-    return address(m_owners[ownerIndex + 1]);
-  }
-
-  // As return statement unavailable in fallback, explicit the method here
-
-  function hasConfirmed(bytes32 _operation, address _owner) external constant returns (bool) {
-    return _walletLibrary.delegatecall(msg.data);
-  }
-
-  function isOwner(address _addr) constant returns (bool) {
-    return _walletLibrary.delegatecall(msg.data);
-  }
-
-  // FIELDS
-  address constant _walletLibrary = 0xcafecafecafecafecafecafecafecafecafecafe;
-
-  // the number of owners that must confirm the same operation before it is run.
-  uint public m_required;
-  // pointer used to find a free slot in m_owners
-  uint public m_numOwners;
-
-  uint public m_dailyLimit;
-  uint public m_spentToday;
-  uint public m_lastDay;
-
-  // list of owners
-  uint[256] m_owners;
-}
\ No newline at end of file
diff --git a/samples/ether_send.sol b/solidity_examples/ether_send.sol
similarity index 100%
rename from samples/ether_send.sol
rename to solidity_examples/ether_send.sol
diff --git a/samples/integer_overflow.sol b/solidity_examples/integer_overflow.sol
similarity index 100%
rename from samples/integer_overflow.sol
rename to solidity_examples/integer_overflow.sol
diff --git a/solidity_examples/reentrancy.sol b/solidity_examples/reentrancy.sol
new file mode 100644
index 00000000..78210aa8
--- /dev/null
+++ b/solidity_examples/reentrancy.sol
@@ -0,0 +1,23 @@
+contract Reentrancy {
+
+  mapping(address => uint) public balances;
+
+  function donate(address _to) public payable {
+    balances[_to] += msg.value;
+  }
+
+  function balanceOf(address _who) public constant returns (uint balance) {
+    return balances[_who];
+  }
+
+  function withdraw(uint _amount) public {
+    if(balances[msg.sender] >= _amount) {
+      if(msg.sender.call.value(_amount)()) {
+        _amount;
+      }
+      balances[msg.sender] -= _amount;
+    }
+  }
+
+  function() payable {}
+}
\ No newline at end of file
diff --git a/solidity_examples/underflow.sol b/solidity_examples/underflow.sol
new file mode 100644
index 00000000..6ecef5df
--- /dev/null
+++ b/solidity_examples/underflow.sol
@@ -0,0 +1,20 @@
+contract Under {
+
+  mapping(address => uint) balances;
+  uint public totalSupply;
+
+  function Token(uint _initialSupply) {
+    balances[msg.sender] = totalSupply = _initialSupply;
+  }
+
+  function sendeth(address _to, uint _value) public returns (bool) {
+    require(balances[msg.sender] - _value >= 0);
+    balances[msg.sender] -= _value;
+    balances[_to] += _value;
+    return true;
+  }
+
+  function balanceOf(address _owner) public constant returns (uint balance) {
+    return balances[_owner];
+  }
+}
\ No newline at end of file