Theorem subsf

Description: Function statement for surreal subtraction. (Contributed by Scott Fenton, 17-May-2025)

	Ref	Expression
Assertion	subsf	Could not format assertion : No typesetting found for |- -s : ( No X. No ) --> No with typecode |-

Proof

Step	Hyp	Ref	Expression
1		negscl	Could not format ( y e. No -> ( -us ` y ) e. No ) : No typesetting found for |- ( y e. No -> ( -us ` y ) e. No ) with typecode |-
2		addscl	Could not format ( ( x e. No /\ ( -us ` y ) e. No ) -> ( x +s ( -us ` y ) ) e. No ) : No typesetting found for |- ( ( x e. No /\ ( -us ` y ) e. No ) -> ( x +s ( -us ` y ) ) e. No ) with typecode |-
3	1 2	sylan2	Could not format ( ( x e. No /\ y e. No ) -> ( x +s ( -us ` y ) ) e. No ) : No typesetting found for |- ( ( x e. No /\ y e. No ) -> ( x +s ( -us ` y ) ) e. No ) with typecode |-
4	3	rgen2	Could not format A. x e. No A. y e. No ( x +s ( -us ` y ) ) e. No : No typesetting found for |- A. x e. No A. y e. No ( x +s ( -us ` y ) ) e. No with typecode |-
5		df-subs	Could not format -s = ( x e. No , y e. No |-> ( x +s ( -us ` y ) ) ) : No typesetting found for |- -s = ( x e. No , y e. No |-> ( x +s ( -us ` y ) ) ) with typecode |-
6	5	fmpo	Could not format ( A. x e. No A. y e. No ( x +s ( -us ` y ) ) e. No <-> -s : ( No X. No ) --> No ) : No typesetting found for |- ( A. x e. No A. y e. No ( x +s ( -us ` y ) ) e. No <-> -s : ( No X. No ) --> No ) with typecode |-
7	4 6	mpbi	Could not format -s : ( No X. No ) --> No : No typesetting found for |- -s : ( No X. No ) --> No with typecode |-