Claude Quitte wrote in his e-mail message of 1995/11/30

I have a warning using the construction x -> f(x, i) where i is the
parameter of a loop. It seems that G.A.P. builds a function with two
parameters x, i and says "i undefined global variable" (it's only a
warning).

A := [12, 56, 45, 2, 76, 11, 7] ;
for i in [0..2] do
    Print(" elemts = ", i, " mod 3 : ",
          Filtered(A, x -> RemInt(x, 3) = i), "\n") ;
od ;

GAP emits a warning if the body of a function (in this example the body
is 'RemInt(x,3) = i') contains reference to a global variable (in this
example 'i'), which at the time the function is *read* does not have an
assigned value. And since the entire loop is read before iterating
starts, you get the warning. To suppress the warning, simply assign a
value to 'i'.

A := [12, 56, 45, 2, 76, 11, 7] ;
i := "shut up";
for i in [0..2] do
    Print(" elemts = ", i, " mod 3 : ",
          Filtered(A, x -> RemInt(x, 3) = i), "\n") ;
od ;

Kindly,

Martin.

-- .- .-. - .. -.  .-.. --- ...- . ...  .- -. -. .. -.- .-
Martin Sch"onert,   Martin.Schoenert@Math.RWTH-Aachen.DE,   +49 241 804551
Lehrstuhl D f"ur Mathematik, Templergraben 64, RWTH, 52056 Aachen, Germany