functions in gcd.i -

             factorize(x)  
 
     return list of prime factors of X and their powers as an n-by-2  
     array.  May include a large non-prime factor if X exceeds 3e9.  
     In any event, product(result(,1)^result(,2)) will equal abs(X).  
     X must be a scalar integer type.  

             gcd(a,b)  
 
     returns the GCD (greatest common divisor) of A and B, which must  
     be one of the integer data types.  A and B may be conformable  
     arrays; the semantics of the gcd call are the same as any other  
     binary operation.  Uses Euclid's celebrated algorithm.  
     The absolute values of A and B are taken before the operation  
     commences; if either A or B is 0, the return value will be 0.  

             is_prime(x)  
 
     return non-zero if and only if X (which must be a scalar integer)  
     is prime.  May return a false positive if X is greater than about  
     3e9, since at most 20000 candidate factors are checked.  
     The absolute value of X is taken first; zero is not prime, but 1 is.  

             lcm(a,b)  
 
     returns the LCM (least common multiple) of A and B, which must  
     be one of the integer data types.  A and B may be conformable  
     arrays; the semantics of the lcm call are the same as any other  
     binary operation.  
     The absolute values of A and B are taken before the operation  
     commences; if either A or B is 0, the return value will be 0.