In CAST, one could generalize an operator expression in the following manner:
<&i:N: x[i] > -> y-
The LHS expression is the conjunction (AND) of nodes x[0] through x[N-1]. HAC also provides an equivalent construct:
(&:i:N: x[i] ) -> y-
The other operator which may be used in a loop expression is | (OR).
NOTE: expression loops whose range is empty (e.g. i:0:) are yet undefined, and the current compiler implementation rejects them at unroll time.