(VAR X Y )
(STRATEGY CONTEXTSENSITIVE
        (f 1) 
        (if 1 2) 
        (c ) 
        (true ) 
        (false ) 
)
(RULES 
        f(X) -> if(X, c, f(true))
        if(true, X, Y) -> X
        if(false, X, Y) -> Y
        
)