OPTIONS(/E/C/-Q/-A/-I/-D);
COMMENT Procedure RSUM calculates the sum of the array A
A[1] + ... + A[N].
;
REAL PROCEDURE rsum(a,n); ARRAY a; INTEGER n;
BEGIN INTEGER i; REAL s;
OPTIONS(/A); s:= a[1]; a[n]:= a[n];; OPTIONS(/-A);
FOR i:= 2 STEP 1 UNTIL n DO s:= s + a[i];
rsum:= s
END of rsum;