1 | w:Alph*, s:((x,y:Alph*//(x R y)) (x,y:Alph*//(x R y))).
( < (x,y:Alph*//(x R y)) (x,y:Alph*//(x R y)), a,xy. xy/x,y. < a.x,a.y > > :w s) = (s/x,y. < w@ x,w@ y > ) |
2 | 17. w:Alph*, s:((x,y:Alph*//(x R y)) (x,y:Alph*//(x R y))).
( < (x,y:Alph*//(x R y)) (x,y:Alph*//(x R y)), a,xy. xy/x,y. < a.x,a.y > > :w s) = (s/x,y. < w@ x,w@ y > ) Dec(x Rg y) |