math : CONTEXT = BEGIN gcd(m : NATURAL, n : NATURAL) : NATURAL = IF n = 0 THEN m ELSE LET r : NATURAL = m MOD n IN IF r = 0 THEN n ELSE gcd(n,r) ENDIF ENDIF; lcm(m : NATURAL, n : NATURAL) : NATURAL = IF m = n THEN m ELSIF m MOD n = 0 THEN m ELSIF n MOD m = 0 THEN n ELSE (m DIV gcd(m,n)) * n ENDIF; END