jacobi ( a m -- n )

Vocabulary

math.extras

Inputs

a	an object
m	an object

Outputs

n

an object

Definition

USING: kernel math math.extras.private sequences ;

IN: math.extras

: jacobi ( a m -- n )
    check-jacobi [ mod' ] keep 1
    [ pick zero? ] [
        [ pick even? ] [
            [ 2 / ] 2dip over 8 mod' { 3 5 } member?
            [ neg ] when
        ] while swapd 2over [ 4 mod' 3 = ] both? [ neg ] when
        [ [ mod' ] keep ] dip
    ] until [ nip 1 = ] dip 0 ? ;