.Marked_/\Marked_./Marked_\eyx\(x,x)e/(x,x)e.(e,x)x.(x,e)x\(e,x)x/(x,e)x.(x,\(x,y))y.(/(y,x),x)y\(x,.(x,y))y/(.(y,x),x)y/(x,\(y,x))y\(/(x,y),x)y\(x,x)e/(x,x)e.(e,x)x.(x,e)x\(e,x)x/(x,e)x.(x,\(x,y))y.(/(y,x),x)y\(x,.(x,y))y/(.(y,x),x)y/(x,\(y,x))y\(/(x,y),x)y