Theorem decadd

Description: Add two numerals M and N (no carry). (Contributed by Mario Carneiro, 18-Feb-2014) (Revised by AV, 6-Sep-2021)

	Ref	Expression
Hypotheses	decma.a	$$⊢A\in {\mathbb{N}}_0$$
	decma.b	$$⊢B\in {\mathbb{N}}_0$$
	decma.c	$$⊢C\in {\mathbb{N}}_0$$
	decma.d	$$⊢D\in {\mathbb{N}}_0$$
	decma.m	No typesetting found for |- M = ; A B with typecode |-
	decma.n	No typesetting found for |- N = ; C D with typecode |-
	decadd.e	$$⊢A+C=E$$
	decadd.f	$$⊢B+D=F$$
Assertion	decadd	Could not format assertion : No typesetting found for |- ( M + N ) = ; E F with typecode |-

Proof

Step	Hyp	Ref	Expression
1		decma.a	$$⊢A\in {\mathbb{N}}_0$$
2		decma.b	$$⊢B\in {\mathbb{N}}_0$$
3		decma.c	$$⊢C\in {\mathbb{N}}_0$$
4		decma.d	$$⊢D\in {\mathbb{N}}_0$$
5		decma.m	Could not format M = ; A B : No typesetting found for |- M = ; A B with typecode |-
6		decma.n	Could not format N = ; C D : No typesetting found for |- N = ; C D with typecode |-
7		decadd.e	$$⊢A+C=E$$
8		decadd.f	$$⊢B+D=F$$
9		10nn0	$$⊢10\in {\mathbb{N}}_0$$
10		dfdec10	Could not format ; A B = ( ( ; 1 0 x. A ) + B ) : No typesetting found for |- ; A B = ( ( ; 1 0 x. A ) + B ) with typecode |-
11	5 10	eqtri	$$⊢M=10A+B$$
12		dfdec10	Could not format ; C D = ( ( ; 1 0 x. C ) + D ) : No typesetting found for |- ; C D = ( ( ; 1 0 x. C ) + D ) with typecode |-
13	6 12	eqtri	$$⊢N=10C+D$$
14	9 1 2 3 4 11 13 7 8	numadd	$$⊢M+N=10E+F$$
15		dfdec10	Could not format ; E F = ( ( ; 1 0 x. E ) + F ) : No typesetting found for |- ; E F = ( ( ; 1 0 x. E ) + F ) with typecode |-
16	14 15	eqtr4i	Could not format ( M + N ) = ; E F : No typesetting found for |- ( M + N ) = ; E F with typecode |-