@staticmethod<EOL><INDENT>def _unsigned_sub_overflow(state, a, b):<DEDENT>
cond = Operators.UGT(b, a)<EOL>return cond<EOL>
Sign extend the value to 512 bits and check the result can be represented
 in 256. Following there is a 32 bit excerpt of this condition:

a  -  b   ffffffff bfffffff 80000001 00000000 00000001 3ffffffff 7fffffff
ffffffff     True     True     True    False     True     True     True
bfffffff     True     True     True    False    False     True     True
80000001     True     True     True    False    False     True     True
00000000    False    False    False    False    False     True    False
00000001     True    False    False    False    False     True    False
ffffffff     True     True     True     True     True     True     True
7fffffff     True     True     True    False    False     True    False