bool-smallstep.hs

data B = T | F | NOT B | AND B B | OR B B
	deriving(Eq, Show)

prog :: B
prog = OR (AND F (NOT T)) (NOT F)

smallStepB :: B -> B
smallStepB (NOT T) = F
smallStepB (NOT F) = T
smallStepB (NOT b) = (NOT (smallStepB b))
smallStepB (OR F b) = b
smallStepB (OR T b) = T
smallStepB (OR b1 b2) = (OR (smallStepB b1) b2)
smallStepB (AND F b) = F
smallStepB (AND T b) = b
smallStepB (AND b1 b2) = (AND (smallStepB b1) b2)

ssInterpreterB :: B -> B
ssInterpreterB b = if (isFinalB b) then b else (ssInterpreterB (smallStepB b))

isFinalB :: B -> Bool
isFinalB T = True
isFinalB F = True
isFinalB _ = False