What Am I Missing (HP-71B)

[Les Bell]

(11-03-2014 06:08 AM)Gerson W. Barbosa Wrote:  10 OPTION BASE 0
20 DIM A(1), B(1)
30 MAT INPUT A,B
40 DISP DOT(A,B)

Or

40 DISP A(0)*B(0)+A(1)*B(1)

if no Math ROM.

But this doesn't answer your question, I fear.

Oh, a Math ROM would be bliss, but I don't have one (would need it for the MAT INPUT A,B, too, I think?).

Yes, the real problem is the "Illegal context" error messages on what looks like just about the simplest DEF FN examples. I must be overlooking something very obvious, but I can't think what. . .