Metamath Proof Explorer


Theorem adds32d

Description: Commutative/associative law that swaps the last two terms in a triple sum. (Contributed by Scott Fenton, 22-Jan-2025)

Ref Expression
Hypotheses addsassd.1 φANo
addsassd.2 φBNo
addsassd.3 φCNo
Assertion adds32d Could not format assertion : No typesetting found for |- ( ph -> ( ( A +s B ) +s C ) = ( ( A +s C ) +s B ) ) with typecode |-

Proof

Step Hyp Ref Expression
1 addsassd.1 φANo
2 addsassd.2 φBNo
3 addsassd.3 φCNo
4 2 3 addscomd Could not format ( ph -> ( B +s C ) = ( C +s B ) ) : No typesetting found for |- ( ph -> ( B +s C ) = ( C +s B ) ) with typecode |-
5 4 oveq2d Could not format ( ph -> ( A +s ( B +s C ) ) = ( A +s ( C +s B ) ) ) : No typesetting found for |- ( ph -> ( A +s ( B +s C ) ) = ( A +s ( C +s B ) ) ) with typecode |-
6 1 2 3 addsassd Could not format ( ph -> ( ( A +s B ) +s C ) = ( A +s ( B +s C ) ) ) : No typesetting found for |- ( ph -> ( ( A +s B ) +s C ) = ( A +s ( B +s C ) ) ) with typecode |-
7 1 3 2 addsassd Could not format ( ph -> ( ( A +s C ) +s B ) = ( A +s ( C +s B ) ) ) : No typesetting found for |- ( ph -> ( ( A +s C ) +s B ) = ( A +s ( C +s B ) ) ) with typecode |-
8 5 6 7 3eqtr4d Could not format ( ph -> ( ( A +s B ) +s C ) = ( ( A +s C ) +s B ) ) : No typesetting found for |- ( ph -> ( ( A +s B ) +s C ) = ( ( A +s C ) +s B ) ) with typecode |-