| Step | Hyp | Ref | Expression | 
						
							| 1 |  | frmdmnd.m |  | 
						
							| 2 |  | eqidd |  | 
						
							| 3 |  | eqidd |  | 
						
							| 4 |  | eqid |  | 
						
							| 5 |  | eqid |  | 
						
							| 6 | 1 4 5 | frmdadd |  | 
						
							| 7 | 1 4 | frmdelbas |  | 
						
							| 8 | 1 4 | frmdelbas |  | 
						
							| 9 |  | ccatcl |  | 
						
							| 10 | 7 8 9 | syl2an |  | 
						
							| 11 | 6 10 | eqeltrd |  | 
						
							| 12 | 11 | 3adant1 |  | 
						
							| 13 | 1 4 | frmdbas |  | 
						
							| 14 | 13 | 3ad2ant1 |  | 
						
							| 15 | 12 14 | eleqtrrd |  | 
						
							| 16 |  | simpr1 |  | 
						
							| 17 | 16 7 | syl |  | 
						
							| 18 |  | simpr2 |  | 
						
							| 19 | 18 8 | syl |  | 
						
							| 20 |  | simpr3 |  | 
						
							| 21 | 1 4 | frmdelbas |  | 
						
							| 22 | 20 21 | syl |  | 
						
							| 23 |  | ccatass |  | 
						
							| 24 | 17 19 22 23 | syl3anc |  | 
						
							| 25 | 16 18 10 | syl2anc |  | 
						
							| 26 | 13 | adantr |  | 
						
							| 27 | 25 26 | eleqtrrd |  | 
						
							| 28 | 1 4 5 | frmdadd |  | 
						
							| 29 | 27 20 28 | syl2anc |  | 
						
							| 30 |  | ccatcl |  | 
						
							| 31 | 19 22 30 | syl2anc |  | 
						
							| 32 | 31 26 | eleqtrrd |  | 
						
							| 33 | 1 4 5 | frmdadd |  | 
						
							| 34 | 16 32 33 | syl2anc |  | 
						
							| 35 | 24 29 34 | 3eqtr4d |  | 
						
							| 36 | 16 18 6 | syl2anc |  | 
						
							| 37 | 36 | oveq1d |  | 
						
							| 38 | 1 4 5 | frmdadd |  | 
						
							| 39 | 18 20 38 | syl2anc |  | 
						
							| 40 | 39 | oveq2d |  | 
						
							| 41 | 35 37 40 | 3eqtr4d |  | 
						
							| 42 |  | wrd0 |  | 
						
							| 43 | 42 13 | eleqtrrid |  | 
						
							| 44 | 1 4 5 | frmdadd |  | 
						
							| 45 | 43 44 | sylan |  | 
						
							| 46 | 7 | adantl |  | 
						
							| 47 |  | ccatlid |  | 
						
							| 48 | 46 47 | syl |  | 
						
							| 49 | 45 48 | eqtrd |  | 
						
							| 50 | 1 4 5 | frmdadd |  | 
						
							| 51 | 50 | ancoms |  | 
						
							| 52 | 43 51 | sylan |  | 
						
							| 53 |  | ccatrid |  | 
						
							| 54 | 46 53 | syl |  | 
						
							| 55 | 52 54 | eqtrd |  | 
						
							| 56 | 2 3 15 41 43 49 55 | ismndd |  |