Metamath Proof Explorer


Theorem adds42d

Description: Rearrangement of four terms in a surreal sum. (Contributed by Scott Fenton, 5-Feb-2025)

Ref Expression
Hypotheses adds4d.1 φANo
adds4d.2 φBNo
adds4d.3 φCNo
adds4d.4 φDNo
Assertion adds42d Could not format assertion : No typesetting found for |- ( ph -> ( ( A +s B ) +s ( C +s D ) ) = ( ( A +s C ) +s ( D +s B ) ) ) with typecode |-

Proof

Step Hyp Ref Expression
1 adds4d.1 φANo
2 adds4d.2 φBNo
3 adds4d.3 φCNo
4 adds4d.4 φDNo
5 1 2 3 4 adds4d Could not format ( ph -> ( ( A +s B ) +s ( C +s D ) ) = ( ( A +s C ) +s ( B +s D ) ) ) : No typesetting found for |- ( ph -> ( ( A +s B ) +s ( C +s D ) ) = ( ( A +s C ) +s ( B +s D ) ) ) with typecode |-
6 2 4 addscomd Could not format ( ph -> ( B +s D ) = ( D +s B ) ) : No typesetting found for |- ( ph -> ( B +s D ) = ( D +s B ) ) with typecode |-
7 6 oveq2d Could not format ( ph -> ( ( A +s C ) +s ( B +s D ) ) = ( ( A +s C ) +s ( D +s B ) ) ) : No typesetting found for |- ( ph -> ( ( A +s C ) +s ( B +s D ) ) = ( ( A +s C ) +s ( D +s B ) ) ) with typecode |-
8 5 7 eqtrd Could not format ( ph -> ( ( A +s B ) +s ( C +s D ) ) = ( ( A +s C ) +s ( D +s B ) ) ) : No typesetting found for |- ( ph -> ( ( A +s B ) +s ( C +s D ) ) = ( ( A +s C ) +s ( D +s B ) ) ) with typecode |-