(opposite) ( e1 e2 quot: ( edge -- edge' ) -- edge )

Vocabulary

euler.b-rep

Inputs

e1	an object
e2	an object
quot	a quotation with stack effect ( edge -- edge' )

Outputs

edge

an object

Definition

USING: kernel ;

IN: euler.b-rep

:: (opposite) ( e1 e2 quot: ( edge -- edge' ) -- edge )
    e1 quot call :> e0 e0 e2 eq?
    [ e1 ] [ e0 e2 quot (opposite) ] if ; inline recursive