On: BYTE Magazine: The C Language (1983)

[ufo]

It does look similar to the ALGOL 60 syntax for procedures:

https://en.wikipedia.org/wiki/Algol_60#ALGOL_60

   procedure Absmax(a) Size:(n, m) Result:(y) Subscripts:(i, k);
        value n, m; array a; integer n, m, i, k; real y;
    comment The absolute greatest element of the matrix a, of size n by m,
        is transferred to y, and the subscripts of this element to i and k;
    begin
        integer p, q;
        y := 0; i := k := 1;
        for p := 1 step 1 until n do
            for q := 1 step 1 until m do
                if abs(a[p, q]) > y then
                    begin y := abs(a[p, q]);
                        i := p; k := q
                    end
    end Absmax