def make_FSM(length):
s = MK85(verbose=0)
states = [s.BitVec('states_%d' % i, BIT_WIDTH) for i in range(length)]
inputs = [s.BitVec('inputs_%d' % i, BIT_WIDTH) for i in range(length - 1)]
# initial state:
s.add(states[0] == 0)
# the last state must be equal to one of the acceping states
s.add(Or(*[states[length - 1] == i for i in ACCEPTING_STATES]))
# all states are in limits...
for i in range(length):
s.add(And(states[i] >= 0, states[i] <= 24))
# redundant, though. however, we are not interesting in non-matched inputs, right?
s.add(states[i] != INVALID_STATE)
# "insert" transition() functions between subsequent states
for i in range(length - 1):
s.add(states[i + 1] == transition(s, states[i], inputs[i]))
# enumerate results:
results = []
while s.check():
m = s.model()
#print m
print_model(m, length, inputs)
# add the current solution negated:
tmp = []
for pair in m:
tmp.append(s.var_by_name(pair) == m[pair])
s.add(expr.Not(And(*tmp)))
def factor(n):
print "factoring", n
s = MK85()
#TODO in1,in2,out=Bitvecs('in1 in2 out', 64)
# TODO: 64-bit
in1 = s.BitVec('in1', 32)
in2 = s.BitVec('in2', 32)
out = s.BitVec('out', 32)
s.add(out == n)
s.add(s.BVMulNoOverflow(in1, in2) == out)
# inputs cannot be negative and must be non-1:
s.add(in1 > 1)
s.add(in2 > 1)
if s.check() == False:
print n, "is prime (unsat)"
return [n]
m = s.model()
# get inputs of multiplier:
in1_n = m["in1"]
in2_n = m["in2"]
print "factors of", n, "are", in1_n, "and", in2_n
# factor factors recursively:
rt = sorted(factor(in1_n) + factor(in2_n))
# self-test:
assert reduce(mul, rt, 1) == n
return rt
# MS Excel or LibreOffice style.
# first top-left cell is A0, not A1
def coord_to_name(R, C):
return "ABCDEFGHIJKLMNOPQRSTUVWXYZ"[R] + str(C)
# open file and parse it as list of lists:
f = open(sys.argv[1], "r")
# filter(None, ...) to remove empty sublists:
ar = filter(None, [item.rstrip().split() for item in f.readlines()])
f.close()
WIDTH = len(ar[0])
HEIGHT = len(ar)
s = MK85()
# cells{} is a dictionary with keys like "A0", "B9", etc:
cells = {}
for R in range(HEIGHT):
for C in range(WIDTH):
name = coord_to_name(R, C)
cells[name] = s.BitVec(name, 32)
cur_R = 0
cur_C = 0
for row in ar:
for c in row:
# string like "A0+B2" becomes "cells["A0"]+cells["B2"]":
c = re.sub(r'([A-Z]{1}[0-9]+)', r'cells["\1"]', c)
from MK85 import *
# see: https://yurichev.com/blog/TAOCP_713_198/
s=MK85(verbose=0)
# FIXME: must work with 22-bit bitvecs:
a=s.BitVec('a', 32)
b=s.BitVec('b', 32)
c=s.BitVec('c', 32)
# make a,c more aesthetically appealing:
s.add((a&0xffff)==0)
s.add((c&0xffff00)==0)
def bytes_in_UTF8_seq(x):
if (x>>7)==0:
return 1
if (x>>5)==0b110:
return 2
if (x>>4)==0b1110:
return 3
if (x>>3)==0b11110:
return 4
# invalid 1st byte
return None
for x in range(256):
t=bytes_in_UTF8_seq(x)
if t!=None:
#print x, t