The output of this program is simply wrong.
f[0](z,t):=rw5*z^k+rw5*t^k;
S:"ddc";
M[0]:5;
for j:1 thru slength(S) step 1 do (if charat(S, j)="a" then
(M[j]:M[j-1]-2, h[j](z,t):=(M[j]
+1)*(M[j]+2)*integrate(f[j-1](z,t), t)/2, f[j](z,
t):=-(1/4)*integrate(h[j](z, t)
-h[j](t,
z), z))
elseif charat(S, j)="b" then (M[j]:M[j-1]-2, h[j](z,t):=Mu*(M[j]
+1)*(M[j]+2)*integrate(f[j-1](z,t), t)/2, f[j](z, t):=(h[j](z,t)+h[j](t,z))/2)
elseif charat(S, j)="c" then (M[j]:M[j-1]-1, f[j](z,
t):=(-1/2)*(M[j]+1)*integrate(f[j
-1](z,t), z))
elseif charat(S, j)="d" then (M[j]:M[j-1]-2, f[j](z,
t):=-(M[j]+1)*(M[j]+2)*integrate(integrate(f[j
-1](z,t), z), t))
elseif charat(S, j)="e" then (M[j]:M[j-1]-1, f[j](z,
t):=-Mu*(M[j]+1)*f[j-1](z, t))
elseif charat(S, j)="f" then (M[j]:M[j-1]-1, f[j](z,
t):=(M[j]+1)*integrate(integrate(f[j
-1](z,t), z), t)/Mu)
);
Even f[1] (z, t) equals wrong expression.
Would anybody be so kind as to show me my mistake?