CMIS 242

Stack Homework

Using the Postfix.java as a base, make a postfix boolean expression
evaluator program.  This is very similar to the postfix integer
expression evaluator except the operands can only be true and false
and the operators are !, && and ||, (i.e. the three logical operators).

Example postfix boolean expressions:

true false &&
   postfix for: true && false  = false
  
true false ! &&
   postfix for: true && !false  = true

true true ! false || ! && true false && ||
   postfix for: true && !(!true || false) || (true && false)  = true

true !
   postfix for: !true  = false

true true false ! && || false || false false && true ! && || true ||
   postfix for: true || true && !false || false || false && false && !true || true   = true

true ! false && true false && || true ||
   postfix for: !true && false || true && false || true   = true

true false && ! true false true || && ||
   postfix for: !(true && false) || true && (false || true)   = true

true false && true false && || true || !
   postfix for: !(true && false || true && false || true)   = false


The program is analogous to the Postfix.java.  The stack will contain Boolean objects.

You can use the code of Postfix, changing each Integer to Boolean
and each int to boolean (notice the capital letters).

! is a unary operator, so only the most recently pushed operand is
popped off the stack and has the ! operator applied to it.

Name your class 'YourlastnamePostfix' please.
Submit the .java file to Tycho.