| Step | Hyp | Ref | Expression | 
						
							| 1 |  | frmdup3.m |  | 
						
							| 2 |  | frmdup3.b |  | 
						
							| 3 |  | frmdup3.u |  | 
						
							| 4 |  | eqid |  | 
						
							| 5 | 4 2 | mhmf |  | 
						
							| 6 | 5 | ad2antrl |  | 
						
							| 7 | 1 4 | frmdbas |  | 
						
							| 8 | 7 | 3ad2ant2 |  | 
						
							| 9 | 8 | adantr |  | 
						
							| 10 | 9 | feq2d |  | 
						
							| 11 | 6 10 | mpbid |  | 
						
							| 12 | 11 | feqmptd |  | 
						
							| 13 |  | simplrl |  | 
						
							| 14 |  | simpr |  | 
						
							| 15 | 3 | vrmdf |  | 
						
							| 16 | 15 | 3ad2ant2 |  | 
						
							| 17 | 8 | feq3d |  | 
						
							| 18 | 16 17 | mpbird |  | 
						
							| 19 | 18 | ad2antrr |  | 
						
							| 20 |  | wrdco |  | 
						
							| 21 | 14 19 20 | syl2anc |  | 
						
							| 22 | 4 | gsumwmhm |  | 
						
							| 23 | 13 21 22 | syl2anc |  | 
						
							| 24 |  | simpll2 |  | 
						
							| 25 | 1 3 | frmdgsum |  | 
						
							| 26 | 24 14 25 | syl2anc |  | 
						
							| 27 | 26 | fveq2d |  | 
						
							| 28 |  | coass |  | 
						
							| 29 |  | simplrr |  | 
						
							| 30 | 29 | coeq1d |  | 
						
							| 31 | 28 30 | eqtr3id |  | 
						
							| 32 | 31 | oveq2d |  | 
						
							| 33 | 23 27 32 | 3eqtr3d |  | 
						
							| 34 | 33 | mpteq2dva |  | 
						
							| 35 | 12 34 | eqtrd |  |