import "StandardLibrary" Concat ?x ?y ?z :- @bbf 1 ?z = ?x + ?y @bfb 0.5 startsWith ?z ?x ?y = drop (length ?x) ?z @fbb 0.5 endsWith ?z ?y ?x = take (length ?z - length ?y) ?z main = select ?y where Concat "Hello " ?y "Hello world!" -- [world!]