Multiple patterns for zero-dimensional tables

[tueda]

It would be nice to have the possibility to define multiple patterns for a zero-dimensional table. To avoid syntactic problems, in the following I would use Define <zero-dimensional table> = <rhs>, instead of Table and Fill, but the meaning should be clear.

CF f1,f2,f3;
S x2,x3;
V p2,p3;

* Zip two functions as
*   zip(f1,f2(a1,...,aN),f3(b1,...,bN)) -> f1(a1,b1,...,aN,bN).

Define zip(f1?(?a1),f2?(x2?,?a2),f3?(x3?,?a3))
  = zip(f1(?a1,x2,x3),f2(?a2),f3(?a3));

Define zip(f1?(?a1),f2?(p2?,?a2),f3?(p3?,?a3))
  = zip(f1(?a1,p2,p3),f2(?a2),f3(?a3));

Define zip(f1?(?a1),f2?(),f3?());
  = f1(?a1);

* Example

Auto S a,b;
Auto V p,q;
CF f;

L F1 = zip(f,f(<a1>,...,<a5>),f(<b1>,...,<b5>));
L F2 = zip(f,f(<p1>,...,<p5>),f(<q1>,...,<q5>));

P;
.end

I would expect FORM automatically tries to apply

repeat;
  id ifmatch->continue, zip(f1?(?a1),f2?(x2?,?a2),f3?(x3?,?a3))
    = zip(f1(?a1,x2,x3),f2(?a2),f3(?a3));
  id ifmatch->continue, zip(f1?(?a1),f2?(p2?,?a2),f3?(p3?,?a3))
    = zip(f1(?a1,p2,p3),f2(?a2),f3(?a3));
  id ifmatch->continue, zip(f1?(?a1),f2?(),f3?());
    = f1(?a1);
label continue;
endrepeat;

and gives the followings in the end:

F1 = f(a1,b1,a2,b2,a3,b3,a4,b4,a5,b5);
F2 = f(p1,q1,p2,q2,p3,q3,p4,q4,p5,q5);