Definition df-pli 10560

Description: Define addition on positive integers. This is a "temporary" set used in the construction of complex numbers df-c 10808, and is intended to be used only by the construction. (Contributed by NM, 26-Aug-1995.) (New usage is discouraged.)

Assertion

Ref	Expression
df-pli	⊢ +N = ( +o ↾ (N × N))

Detailed syntax breakdown of Definition df-pli

Step	Hyp	Ref	Expression
1		cpli 10532	. 2 class +N
2		coa 8264	. . 3 class +o
3		cnpi 10531	. . . 4 class N
4	3, 3	cxp 5578	. . 3 class (N × N)
5	2, 4	cres 5582	. 2 class ( +o ↾ (N × N))
6	1, 5	wceq 1539	1 wff +N = ( +o ↾ (N × N))

This definition is referenced by:  addpiord  10571  dmaddpi  10577