/**
 * is-permutation.h
 *   A procedure for checking permutations.
 */

/**
 * Procedure:
 *   is_permutation
 * Parameters:
 *   a1, an array of ints
 *   a2, an array of ints
 *   size, an integer
 * Purpose:
 *   Determine if the first size elements of a2 are a permutation of 
 *   the first size elements of a1.
 * Produces:
 *   is_perm, an integer that represents a Boolean
 * Preconditions:
 *   0 <= size 
 *   size <= length of a1
 *   size <= length of a2
 * Postconditions:
 *   The first size elements of a2 are a permutation of the first size
 *     elements of a2 iff is_perm is true.
 */
int is_permutation (int a1[], int a2[], int size);