Metamath Proof Explorer


Definition df-gcdOLD

Description: gcdOLD ( A , B ) is the largest positive integer that evenly divides both A and B . (Contributed by Jeff Hoffman, 17-Jun-2008) (New usage is discouraged.)

Ref Expression
Assertion df-gcdOLD
|- gcdOLD ( A , B ) = sup ( { x e. NN | ( ( A / x ) e. NN /\ ( B / x ) e. NN ) } , NN , < )

Detailed syntax breakdown

Step Hyp Ref Expression
0 cA
 |-  A
1 cB
 |-  B
2 0 1 cgcdOLD
 |-  gcdOLD ( A , B )
3 vx
 |-  x
4 cn
 |-  NN
5 cdiv
 |-  /
6 3 cv
 |-  x
7 0 6 5 co
 |-  ( A / x )
8 7 4 wcel
 |-  ( A / x ) e. NN
9 1 6 5 co
 |-  ( B / x )
10 9 4 wcel
 |-  ( B / x ) e. NN
11 8 10 wa
 |-  ( ( A / x ) e. NN /\ ( B / x ) e. NN )
12 11 3 4 crab
 |-  { x e. NN | ( ( A / x ) e. NN /\ ( B / x ) e. NN ) }
13 clt
 |-  <
14 12 4 13 csup
 |-  sup ( { x e. NN | ( ( A / x ) e. NN /\ ( B / x ) e. NN ) } , NN , < )
15 2 14 wceq
 |-  gcdOLD ( A , B ) = sup ( { x e. NN | ( ( A / x ) e. NN /\ ( B / x ) e. NN ) } , NN , < )