 | substitute in the given 'Lc' the LcVars with the given name
-- with the given 'Lc'
substitute :: Lc -> String -> Lc -> Lc
substitute v@(LcVar var) param new | var == param = new
                                   | otherwise    = v
s
substitute :: Lc -> String -> Lc -> Lc
substitute v@(LcVar var) param new | var == param = new
                                   | otherwise    = v
substitute v@(LcVar var) param new | var == param = new
                                   | otherwise    = v