Theorem subsid

Description: Subtraction of a surreal from itself. (Contributed by Scott Fenton, 3-Feb-2025)

	Ref	Expression
Assertion	subsid	Could not format assertion : No typesetting found for |- ( A e. No -> ( A -s A ) = 0s ) with typecode |-

Proof

Step	Hyp	Ref	Expression
1		subsval	Could not format ( ( A e. No /\ A e. No ) -> ( A -s A ) = ( A +s ( -us ` A ) ) ) : No typesetting found for |- ( ( A e. No /\ A e. No ) -> ( A -s A ) = ( A +s ( -us ` A ) ) ) with typecode |-
2	1	anidms	Could not format ( A e. No -> ( A -s A ) = ( A +s ( -us ` A ) ) ) : No typesetting found for |- ( A e. No -> ( A -s A ) = ( A +s ( -us ` A ) ) ) with typecode |-
3		negsid	Could not format ( A e. No -> ( A +s ( -us ` A ) ) = 0s ) : No typesetting found for |- ( A e. No -> ( A +s ( -us ` A ) ) = 0s ) with typecode |-
4	2 3	eqtrd	Could not format ( A e. No -> ( A -s A ) = 0s ) : No typesetting found for |- ( A e. No -> ( A -s A ) = 0s ) with typecode |-