| Step | Hyp | Ref | Expression | 
						
							| 1 |  | wrdfn |  | 
						
							| 2 |  | fnfun |  | 
						
							| 3 | 1 2 | syl |  | 
						
							| 4 | 3 | 3ad2ant1 |  | 
						
							| 5 |  | wrddm |  | 
						
							| 6 |  | difssd |  | 
						
							| 7 |  | oveq2 |  | 
						
							| 8 | 7 | difeq1d |  | 
						
							| 9 | 8 | adantl |  | 
						
							| 10 |  | simpl |  | 
						
							| 11 | 6 9 10 | 3sstr4d |  | 
						
							| 12 | 11 | a1d |  | 
						
							| 13 | 12 | ex |  | 
						
							| 14 | 5 13 | syl |  | 
						
							| 15 | 14 | 3imp |  | 
						
							| 16 | 4 15 | jca |  | 
						
							| 17 |  | dfimafn |  | 
						
							| 18 | 16 17 | syl |  | 
						
							| 19 |  | modsumfzodifsn |  | 
						
							| 20 | 19 | 3ad2antl3 |  | 
						
							| 21 |  | oveq2 |  | 
						
							| 22 | 21 | eqcoms |  | 
						
							| 23 | 22 | eleq1d |  | 
						
							| 24 | 23 | 3ad2ant2 |  | 
						
							| 25 | 24 | adantr |  | 
						
							| 26 | 20 25 | mpbird |  | 
						
							| 27 |  | modfzo0difsn |  | 
						
							| 28 | 27 | 3ad2antl3 |  | 
						
							| 29 |  | oveq2 |  | 
						
							| 30 | 29 | eqcomd |  | 
						
							| 31 | 30 | eqeq2d |  | 
						
							| 32 | 31 | rexbidv |  | 
						
							| 33 | 32 | 3ad2ant2 |  | 
						
							| 34 | 33 | adantr |  | 
						
							| 35 | 28 34 | mpbird |  | 
						
							| 36 |  | fveq2 |  | 
						
							| 37 | 36 | 3ad2ant3 |  | 
						
							| 38 |  | simpl1 |  | 
						
							| 39 |  | elfzoelz |  | 
						
							| 40 | 39 | 3ad2ant3 |  | 
						
							| 41 | 40 | adantr |  | 
						
							| 42 |  | oveq2 |  | 
						
							| 43 | 42 | eleq2d |  | 
						
							| 44 |  | fzo0ss1 |  | 
						
							| 45 | 44 | sseli |  | 
						
							| 46 | 43 45 | biimtrdi |  | 
						
							| 47 | 46 | 3ad2ant2 |  | 
						
							| 48 | 47 | imp |  | 
						
							| 49 |  | cshwidxmod |  | 
						
							| 50 | 49 | eqcomd |  | 
						
							| 51 | 38 41 48 50 | syl3anc |  | 
						
							| 52 | 51 | 3adant3 |  | 
						
							| 53 | 37 52 | eqtrd |  | 
						
							| 54 | 53 | eqeq1d |  | 
						
							| 55 | 26 35 54 | rexxfrd2 |  | 
						
							| 56 | 55 | abbidv |  | 
						
							| 57 | 39 | anim2i |  | 
						
							| 58 | 57 | 3adant2 |  | 
						
							| 59 |  | cshwfn |  | 
						
							| 60 | 58 59 | syl |  | 
						
							| 61 |  | fnfun |  | 
						
							| 62 | 61 | adantl |  | 
						
							| 63 | 42 44 | eqsstrdi |  | 
						
							| 64 | 63 | 3ad2ant2 |  | 
						
							| 65 | 64 | adantr |  | 
						
							| 66 |  | fndm |  | 
						
							| 67 | 66 | adantl |  | 
						
							| 68 | 65 67 | sseqtrrd |  | 
						
							| 69 | 62 68 | jca |  | 
						
							| 70 | 60 69 | mpdan |  | 
						
							| 71 |  | dfimafn |  | 
						
							| 72 | 70 71 | syl |  | 
						
							| 73 | 56 72 | eqtr4d |  | 
						
							| 74 | 18 73 | eqtrd |  |