DEFINE(( (PRL(LAMBDA(L)(COND((NULL L)NIL)((ATOM L)L)((NULL(CDR L))(CAR L)) ((NULL(CDDR L))(LIST(TECK(CAR L))(PRL(CADR L)))) (T(LIST(PRL(CADR L))(TECK(CAR L))(PRL(CADDR L)))) ))) (TECK(LAMBDA(L)((LAMBDA(K)(COND((NULL K)L)(T(CDR K))))(ASSOC L PRTUT)))) (POLISH(LAMBDA(L)(COND((NULL L)NIL)((ATOM L)L)((NULL(CDR L)) (POLISH(CAR L))) ((NULL(CDDR L))(LIST(TACK(CAR L))(POLISH(CADR L)) )) (T(LIST(TACK(CADR L))(POLISH(CAR L))(POLISH(CDDR L)))) ))) (TACK(LAMBDA(L)((LAMBDA(K)(COND((NULL K)L)(T(CDR K))))(ASSOC L PRTIN)))) )) DEFLIS(( (PRTUT((PLUS.+)(MINUS.-)(TIMES.*)(DIVIDE./)(EXPT.**))) (PRTIN((+.PLUS)(-.MINUS)(*.TIMES)(/.DIVIDE)(**.EXPT))) )APVAL) POLISH((X + Y -((COS(X - Y * Z / U))*(EXP(2 - Y)))+(X ** 4))) PRL((PLUS(TIMES X(COS(DIVIDE(PLUS X Y)(LN(TIMES 2 (TIMES V Y)))))) (COS(EXPT 2 X)))) ICLOSE NIL