-- interpret declarations

iDecl :: [Decl] -> [Stm] -> MRSIO (Env, Exp)
iDecl ((DParam ind ty):tail) stm = iDecl ((DVar ind ty):tail) stm
iDecl :: [Decl] -> [Stm] -> MRSIO (Env, Exp)
iDecl ((DParam ind ty):tail) stm = iDecl ((DVar ind ty):tail) stm
iDecl ((DParam ind ty):tail) stm = iDecl ((DVar ind ty):tail) stm