| Step | Hyp | Ref | Expression | 
						
							| 1 |  | frmdmnd.m |  | 
						
							| 2 |  | frmdgsum.u |  | 
						
							| 3 |  | simpl1 |  | 
						
							| 4 |  | simpl2 |  | 
						
							| 5 |  | sswrd |  | 
						
							| 6 | 4 5 | syl |  | 
						
							| 7 |  | simprr |  | 
						
							| 8 | 6 7 | sseldd |  | 
						
							| 9 | 1 2 | frmdgsum |  | 
						
							| 10 | 3 8 9 | syl2anc |  | 
						
							| 11 |  | simpl3 |  | 
						
							| 12 |  | wrdf |  | 
						
							| 13 | 12 | ad2antll |  | 
						
							| 14 | 13 | frnd |  | 
						
							| 15 |  | cores |  | 
						
							| 16 | 14 15 | syl |  | 
						
							| 17 | 2 | vrmdf |  | 
						
							| 18 | 17 | 3ad2ant1 |  | 
						
							| 19 | 18 | ffnd |  | 
						
							| 20 |  | fnssres |  | 
						
							| 21 | 19 4 20 | syl2an2r |  | 
						
							| 22 |  | df-ima |  | 
						
							| 23 |  | simprl |  | 
						
							| 24 | 22 23 | eqsstrrid |  | 
						
							| 25 |  | df-f |  | 
						
							| 26 | 21 24 25 | sylanbrc |  | 
						
							| 27 |  | wrdco |  | 
						
							| 28 | 7 26 27 | syl2anc |  | 
						
							| 29 | 16 28 | eqeltrrd |  | 
						
							| 30 |  | gsumwsubmcl |  | 
						
							| 31 | 11 29 30 | syl2anc |  | 
						
							| 32 | 10 31 | eqeltrrd |  | 
						
							| 33 | 32 | expr |  | 
						
							| 34 | 33 | ssrdv |  | 
						
							| 35 | 34 | ex |  | 
						
							| 36 |  | simpl1 |  | 
						
							| 37 |  | simp2 |  | 
						
							| 38 | 37 | sselda |  | 
						
							| 39 | 2 | vrmdval |  | 
						
							| 40 | 36 38 39 | syl2anc |  | 
						
							| 41 |  | simpr |  | 
						
							| 42 | 41 | s1cld |  | 
						
							| 43 | 40 42 | eqeltrd |  | 
						
							| 44 | 43 | ralrimiva |  | 
						
							| 45 | 18 | ffund |  | 
						
							| 46 | 18 | fdmd |  | 
						
							| 47 | 37 46 | sseqtrrd |  | 
						
							| 48 |  | funimass4 |  | 
						
							| 49 | 45 47 48 | syl2anc |  | 
						
							| 50 | 44 49 | mpbird |  | 
						
							| 51 |  | sstr2 |  | 
						
							| 52 | 50 51 | syl |  | 
						
							| 53 | 35 52 | impbid |  |