let x be Element of X; :: thesis: x is Path of G

x in { W where W is Path of G : verum } ;

then ex y being Path of G st y = x ;

hence x is Path of G ; :: thesis: verum

x in { W where W is Path of G : verum } ;

then ex y being Path of G st y = x ;

hence x is Path of G ; :: thesis: verum