# Definitions DEF A(x,y,a,c) = a+c+x+y; A(x,y,a,c); A(z,z,z,z); A(3,1,2,-5); A(A(a,b,c,d)^2,A(d,c,b,a)^3,b,c); A(z,y,x,w)+3A(u,v,w,x); QUIT