(VAR x y )
(RULES 
        not(x) -> if(x, false, true)
        and(x, y) -> if(x, y, false)
        or(x, y) -> if(x, true, y)
        implies(x, y) -> if(x, y, true)
        =(x, x) -> true
        =(x, y) -> if(x, y, not(y))
        if(true, x, y) -> x
        if(false, x, y) -> y
        if(x, x, if(x, false, true)) -> true
        =(x, y) -> if(x, y, if(y, false, true))
        
)