Metamath Proof Explorer


Theorem mulnegs2d

Description: Product with negative is negative of product. Part of theorem 7 of Conway p. 19. (Contributed by Scott Fenton, 10-Mar-2025)

Ref Expression
Hypotheses mulnegs1d.1 φANo
mulnegs1d.2 φBNo
Assertion mulnegs2d Could not format assertion : No typesetting found for |- ( ph -> ( A x.s ( -us ` B ) ) = ( -us ` ( A x.s B ) ) ) with typecode |-

Proof

Step Hyp Ref Expression
1 mulnegs1d.1 φANo
2 mulnegs1d.2 φBNo
3 2 1 mulnegs1d Could not format ( ph -> ( ( -us ` B ) x.s A ) = ( -us ` ( B x.s A ) ) ) : No typesetting found for |- ( ph -> ( ( -us ` B ) x.s A ) = ( -us ` ( B x.s A ) ) ) with typecode |-
4 2 negscld Could not format ( ph -> ( -us ` B ) e. No ) : No typesetting found for |- ( ph -> ( -us ` B ) e. No ) with typecode |-
5 1 4 mulscomd Could not format ( ph -> ( A x.s ( -us ` B ) ) = ( ( -us ` B ) x.s A ) ) : No typesetting found for |- ( ph -> ( A x.s ( -us ` B ) ) = ( ( -us ` B ) x.s A ) ) with typecode |-
6 1 2 mulscomd Could not format ( ph -> ( A x.s B ) = ( B x.s A ) ) : No typesetting found for |- ( ph -> ( A x.s B ) = ( B x.s A ) ) with typecode |-
7 6 fveq2d Could not format ( ph -> ( -us ` ( A x.s B ) ) = ( -us ` ( B x.s A ) ) ) : No typesetting found for |- ( ph -> ( -us ` ( A x.s B ) ) = ( -us ` ( B x.s A ) ) ) with typecode |-
8 3 5 7 3eqtr4d Could not format ( ph -> ( A x.s ( -us ` B ) ) = ( -us ` ( A x.s B ) ) ) : No typesetting found for |- ( ph -> ( A x.s ( -us ` B ) ) = ( -us ` ( A x.s B ) ) ) with typecode |-