add abs() constant function
add abs() constant function

nunoplopes/alive,rutgers-apl/alive-loops,chubbymaggie/alive,davemenendez/alive,davemenendez/alive,nunoplopes/alive,chubbymaggie/alive,rutgers-apl/alive-loops,chubbymaggie/alive,rutgers-apl/alive-loops,rutgers-apl/alive-loops,chubbymaggie/alive,nunoplopes/alive,nunoplopes/alive