| Step | Hyp | Ref | Expression | 
						
							| 1 |  | simprl |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> w e. No ) | 
						
							| 2 |  | simpl3 |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> B e. No ) | 
						
							| 3 | 1 2 | mulscld |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( w x.s B ) e. No ) | 
						
							| 4 |  | oveq1 |  |-  ( ( A x.s w ) = 1s -> ( ( A x.s w ) x.s B ) = ( 1s x.s B ) ) | 
						
							| 5 | 4 | adantl |  |-  ( ( w e. No /\ ( A x.s w ) = 1s ) -> ( ( A x.s w ) x.s B ) = ( 1s x.s B ) ) | 
						
							| 6 | 5 | adantl |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( ( A x.s w ) x.s B ) = ( 1s x.s B ) ) | 
						
							| 7 |  | simpl1 |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> A e. No ) | 
						
							| 8 | 7 1 2 | mulsassd |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( ( A x.s w ) x.s B ) = ( A x.s ( w x.s B ) ) ) | 
						
							| 9 | 2 | mulslidd |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( 1s x.s B ) = B ) | 
						
							| 10 | 6 8 9 | 3eqtr3d |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> ( A x.s ( w x.s B ) ) = B ) | 
						
							| 11 |  | oveq2 |  |-  ( z = ( w x.s B ) -> ( A x.s z ) = ( A x.s ( w x.s B ) ) ) | 
						
							| 12 | 11 | eqeq1d |  |-  ( z = ( w x.s B ) -> ( ( A x.s z ) = B <-> ( A x.s ( w x.s B ) ) = B ) ) | 
						
							| 13 | 12 | rspcev |  |-  ( ( ( w x.s B ) e. No /\ ( A x.s ( w x.s B ) ) = B ) -> E. z e. No ( A x.s z ) = B ) | 
						
							| 14 | 3 10 13 | syl2anc |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ ( w e. No /\ ( A x.s w ) = 1s ) ) -> E. z e. No ( A x.s z ) = B ) | 
						
							| 15 | 14 | rexlimdvaa |  |-  ( ( A e. No /\ A =/= 0s /\ B e. No ) -> ( E. w e. No ( A x.s w ) = 1s -> E. z e. No ( A x.s z ) = B ) ) | 
						
							| 16 | 15 | imp |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ E. w e. No ( A x.s w ) = 1s ) -> E. z e. No ( A x.s z ) = B ) | 
						
							| 17 |  | oveq2 |  |-  ( x = w -> ( A x.s x ) = ( A x.s w ) ) | 
						
							| 18 | 17 | eqeq1d |  |-  ( x = w -> ( ( A x.s x ) = 1s <-> ( A x.s w ) = 1s ) ) | 
						
							| 19 | 18 | cbvrexvw |  |-  ( E. x e. No ( A x.s x ) = 1s <-> E. w e. No ( A x.s w ) = 1s ) | 
						
							| 20 | 19 | anbi2i |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ E. x e. No ( A x.s x ) = 1s ) <-> ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ E. w e. No ( A x.s w ) = 1s ) ) | 
						
							| 21 |  | oveq2 |  |-  ( y = z -> ( A x.s y ) = ( A x.s z ) ) | 
						
							| 22 | 21 | eqeq1d |  |-  ( y = z -> ( ( A x.s y ) = B <-> ( A x.s z ) = B ) ) | 
						
							| 23 | 22 | cbvrexvw |  |-  ( E. y e. No ( A x.s y ) = B <-> E. z e. No ( A x.s z ) = B ) | 
						
							| 24 | 16 20 23 | 3imtr4i |  |-  ( ( ( A e. No /\ A =/= 0s /\ B e. No ) /\ E. x e. No ( A x.s x ) = 1s ) -> E. y e. No ( A x.s y ) = B ) |