Metamath Proof Explorer


Theorem dfprm2

Description: The positive irreducible elements of ZZ are the prime numbers. This is an alternative way to define Prime . (Contributed by Mario Carneiro, 5-Dec-2014) (Revised by AV, 10-Jun-2019)

Ref Expression
Hypothesis prmirred.i
|- I = ( Irred ` ZZring )
Assertion dfprm2
|- Prime = ( NN i^i I )

Proof

Step Hyp Ref Expression
1 prmirred.i
 |-  I = ( Irred ` ZZring )
2 prmnn
 |-  ( x e. Prime -> x e. NN )
3 1 prmirredlem
 |-  ( x e. NN -> ( x e. I <-> x e. Prime ) )
4 3 bicomd
 |-  ( x e. NN -> ( x e. Prime <-> x e. I ) )
5 2 4 biadanii
 |-  ( x e. Prime <-> ( x e. NN /\ x e. I ) )
6 elin
 |-  ( x e. ( NN i^i I ) <-> ( x e. NN /\ x e. I ) )
7 5 6 bitr4i
 |-  ( x e. Prime <-> x e. ( NN i^i I ) )
8 7 eqriv
 |-  Prime = ( NN i^i I )