| Step | Hyp | Ref | Expression | 
						
							| 1 |  | slemul1ad.1 |  |-  ( ph -> A e. No ) | 
						
							| 2 |  | slemul1ad.2 |  |-  ( ph -> B e. No ) | 
						
							| 3 |  | slemul1ad.3 |  |-  ( ph -> C e. No ) | 
						
							| 4 |  | slemul1ad.4 |  |-  ( ph -> 0s <_s C ) | 
						
							| 5 |  | slemul1ad.5 |  |-  ( ph -> A <_s B ) | 
						
							| 6 | 5 | adantr |  |-  ( ( ph /\ 0s  A <_s B ) | 
						
							| 7 | 1 | adantr |  |-  ( ( ph /\ 0s  A e. No ) | 
						
							| 8 | 2 | adantr |  |-  ( ( ph /\ 0s  B e. No ) | 
						
							| 9 | 3 | adantr |  |-  ( ( ph /\ 0s  C e. No ) | 
						
							| 10 |  | simpr |  |-  ( ( ph /\ 0s  0s  | 
						
							| 11 | 7 8 9 10 | slemul1d |  |-  ( ( ph /\ 0s  ( A <_s B <-> ( A x.s C ) <_s ( B x.s C ) ) ) | 
						
							| 12 | 6 11 | mpbid |  |-  ( ( ph /\ 0s  ( A x.s C ) <_s ( B x.s C ) ) | 
						
							| 13 |  | 0sno |  |-  0s e. No | 
						
							| 14 |  | slerflex |  |-  ( 0s e. No -> 0s <_s 0s ) | 
						
							| 15 | 13 14 | mp1i |  |-  ( ph -> 0s <_s 0s ) | 
						
							| 16 |  | muls01 |  |-  ( A e. No -> ( A x.s 0s ) = 0s ) | 
						
							| 17 | 1 16 | syl |  |-  ( ph -> ( A x.s 0s ) = 0s ) | 
						
							| 18 |  | muls01 |  |-  ( B e. No -> ( B x.s 0s ) = 0s ) | 
						
							| 19 | 2 18 | syl |  |-  ( ph -> ( B x.s 0s ) = 0s ) | 
						
							| 20 | 15 17 19 | 3brtr4d |  |-  ( ph -> ( A x.s 0s ) <_s ( B x.s 0s ) ) | 
						
							| 21 |  | oveq2 |  |-  ( 0s = C -> ( A x.s 0s ) = ( A x.s C ) ) | 
						
							| 22 |  | oveq2 |  |-  ( 0s = C -> ( B x.s 0s ) = ( B x.s C ) ) | 
						
							| 23 | 21 22 | breq12d |  |-  ( 0s = C -> ( ( A x.s 0s ) <_s ( B x.s 0s ) <-> ( A x.s C ) <_s ( B x.s C ) ) ) | 
						
							| 24 | 20 23 | syl5ibcom |  |-  ( ph -> ( 0s = C -> ( A x.s C ) <_s ( B x.s C ) ) ) | 
						
							| 25 | 24 | imp |  |-  ( ( ph /\ 0s = C ) -> ( A x.s C ) <_s ( B x.s C ) ) | 
						
							| 26 |  | sleloe |  |-  ( ( 0s e. No /\ C e. No ) -> ( 0s <_s C <-> ( 0s  | 
						
							| 27 | 13 3 26 | sylancr |  |-  ( ph -> ( 0s <_s C <-> ( 0s  | 
						
							| 28 | 4 27 | mpbid |  |-  ( ph -> ( 0s  | 
						
							| 29 | 12 25 28 | mpjaodan |  |-  ( ph -> ( A x.s C ) <_s ( B x.s C ) ) |