Expert System, solves some logic things

The algorithm is still incomplete and there are many unused funcs I though would be required.

Syntax:

• A + B means AND
• A | B means OR
• A ^ B means XOR
• !A means NOT
• A | B => C + D means if A or B are true, then C and D are also true
• X ^ (A | B) => !K means if left side is true, then K is certainly false
• =AJK describes initial facts, in this case A, J, K are true
• ?XY says that we want to know whether X and Y are true

Example of program input and output:

A => J ^ K
B => X ^ Y
J + !K => !A | C
C => D
=A
?D

( true: A  unknown: D )
Using C => D
  ( true: A  unknown: C, D )
  Using C => D
  No match
  Using J + !K => !A | C
    ( true: A  unknown: C, D, J, K )
    Using C => D
    No match
    Using J + !K => !A | C
    No match
    Using A => J ^ K
    2 possible outcomes
    Trying with ( true: J  false: K )
      ( true: A, J  false: K  unknown: C, D )
      Using C => D
      No match
      Using J + !K => !A | C
      3 possible outcomes
      Trying with ( false: A )
      Conflict
      Trying with ( true: C )
        ( true: A, C, J  false: K  unknown: D )
        Using C => D
        1 possible outcome
        Trying with ( true: D )
          ( true: A, C, D, J  false: K )
          Unknown list is empty, returning
Result: ( true: A, C, D, J  false: K )