var[3] = 0 and var[2] = 1
var[0] = 1 and var[2] = 0 and var[3] = 1
...

#!/usr/bin/env python
from pyparsing import Word, alphas, nums, infixNotation, opAssoc

class BoolAnd():
    def __init__(self, pattern):
        self.args = pattern[0][0::2]

    def __bool__(self):
        return all(bool(a) for a in self.args)

    __nonzero__ = __bool__


class BoolEqual():
    def __init__(self, pattern):
        self.bit_offset = int(pattern[0][1])
        self.value = int(pattern[0][-1])

    def __bool__(self):
        return True if (0xf >> self.bit_offset) & 0x1 == self.value else False # for now, let's assume var == 0xf

    __nonzero__ = __bool__




variable_name   = 'var'
bit_access      = variable_name + '[' + Word(nums) + ']'
multibit_access = variable_name + '[' + Word(nums) + ':' + Word(nums) + ']'
value = Word(nums)

operand = bit_access | multibit_access | Word(nums)

expression = infixNotation(operand,
    [
    ('=',   2, opAssoc.LEFT,  BoolEqual),
    ('AND', 2, opAssoc.LEFT,  BoolAnd),
    ])


p = expression.parseString('var[3] = 1 AND var[1] = 0', True)

print 'SUCCESS' if bool(p) else 'FAIL'