| Step | Hyp | Ref | Expression | 
						
							| 1 |  | gsumval3.b | ⊢ 𝐵  =  ( Base ‘ 𝐺 ) | 
						
							| 2 |  | gsumval3.0 | ⊢  0   =  ( 0g ‘ 𝐺 ) | 
						
							| 3 |  | gsumval3.p | ⊢  +   =  ( +g ‘ 𝐺 ) | 
						
							| 4 |  | gsumval3.z | ⊢ 𝑍  =  ( Cntz ‘ 𝐺 ) | 
						
							| 5 |  | gsumval3.g | ⊢ ( 𝜑  →  𝐺  ∈  Mnd ) | 
						
							| 6 |  | gsumval3.a | ⊢ ( 𝜑  →  𝐴  ∈  𝑉 ) | 
						
							| 7 |  | gsumval3.f | ⊢ ( 𝜑  →  𝐹 : 𝐴 ⟶ 𝐵 ) | 
						
							| 8 |  | gsumval3.c | ⊢ ( 𝜑  →  ran  𝐹  ⊆  ( 𝑍 ‘ ran  𝐹 ) ) | 
						
							| 9 |  | gsumval3.m | ⊢ ( 𝜑  →  𝑀  ∈  ℕ ) | 
						
							| 10 |  | gsumval3.h | ⊢ ( 𝜑  →  𝐻 : ( 1 ... 𝑀 ) –1-1→ 𝐴 ) | 
						
							| 11 |  | gsumval3.n | ⊢ ( 𝜑  →  ( 𝐹  supp   0  )  ⊆  ran  𝐻 ) | 
						
							| 12 |  | gsumval3.w | ⊢ 𝑊  =  ( ( 𝐹  ∘  𝐻 )  supp   0  ) | 
						
							| 13 | 10 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  𝐻 : ( 1 ... 𝑀 ) –1-1→ 𝐴 ) | 
						
							| 14 |  | suppssdm | ⊢ ( ( 𝐹  ∘  𝐻 )  supp   0  )  ⊆  dom  ( 𝐹  ∘  𝐻 ) | 
						
							| 15 | 12 14 | eqsstri | ⊢ 𝑊  ⊆  dom  ( 𝐹  ∘  𝐻 ) | 
						
							| 16 |  | f1f | ⊢ ( 𝐻 : ( 1 ... 𝑀 ) –1-1→ 𝐴  →  𝐻 : ( 1 ... 𝑀 ) ⟶ 𝐴 ) | 
						
							| 17 | 10 16 | syl | ⊢ ( 𝜑  →  𝐻 : ( 1 ... 𝑀 ) ⟶ 𝐴 ) | 
						
							| 18 |  | fco | ⊢ ( ( 𝐹 : 𝐴 ⟶ 𝐵  ∧  𝐻 : ( 1 ... 𝑀 ) ⟶ 𝐴 )  →  ( 𝐹  ∘  𝐻 ) : ( 1 ... 𝑀 ) ⟶ 𝐵 ) | 
						
							| 19 | 7 17 18 | syl2anc | ⊢ ( 𝜑  →  ( 𝐹  ∘  𝐻 ) : ( 1 ... 𝑀 ) ⟶ 𝐵 ) | 
						
							| 20 | 15 19 | fssdm | ⊢ ( 𝜑  →  𝑊  ⊆  ( 1 ... 𝑀 ) ) | 
						
							| 21 | 20 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  𝑊  ⊆  ( 1 ... 𝑀 ) ) | 
						
							| 22 |  | f1ores | ⊢ ( ( 𝐻 : ( 1 ... 𝑀 ) –1-1→ 𝐴  ∧  𝑊  ⊆  ( 1 ... 𝑀 ) )  →  ( 𝐻  ↾  𝑊 ) : 𝑊 –1-1-onto→ ( 𝐻  “  𝑊 ) ) | 
						
							| 23 | 13 21 22 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  ↾  𝑊 ) : 𝑊 –1-1-onto→ ( 𝐻  “  𝑊 ) ) | 
						
							| 24 | 12 | imaeq2i | ⊢ ( 𝐻  “  𝑊 )  =  ( 𝐻  “  ( ( 𝐹  ∘  𝐻 )  supp   0  ) ) | 
						
							| 25 | 7 6 | fexd | ⊢ ( 𝜑  →  𝐹  ∈  V ) | 
						
							| 26 |  | ovex | ⊢ ( 1 ... 𝑀 )  ∈  V | 
						
							| 27 |  | fex | ⊢ ( ( 𝐻 : ( 1 ... 𝑀 ) ⟶ 𝐴  ∧  ( 1 ... 𝑀 )  ∈  V )  →  𝐻  ∈  V ) | 
						
							| 28 | 16 26 27 | sylancl | ⊢ ( 𝐻 : ( 1 ... 𝑀 ) –1-1→ 𝐴  →  𝐻  ∈  V ) | 
						
							| 29 | 10 28 | syl | ⊢ ( 𝜑  →  𝐻  ∈  V ) | 
						
							| 30 |  | f1fun | ⊢ ( 𝐻 : ( 1 ... 𝑀 ) –1-1→ 𝐴  →  Fun  𝐻 ) | 
						
							| 31 | 10 30 | syl | ⊢ ( 𝜑  →  Fun  𝐻 ) | 
						
							| 32 | 31 11 | jca | ⊢ ( 𝜑  →  ( Fun  𝐻  ∧  ( 𝐹  supp   0  )  ⊆  ran  𝐻 ) ) | 
						
							| 33 | 25 29 32 | jca31 | ⊢ ( 𝜑  →  ( ( 𝐹  ∈  V  ∧  𝐻  ∈  V )  ∧  ( Fun  𝐻  ∧  ( 𝐹  supp   0  )  ⊆  ran  𝐻 ) ) ) | 
						
							| 34 | 33 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( ( 𝐹  ∈  V  ∧  𝐻  ∈  V )  ∧  ( Fun  𝐻  ∧  ( 𝐹  supp   0  )  ⊆  ran  𝐻 ) ) ) | 
						
							| 35 |  | imacosupp | ⊢ ( ( 𝐹  ∈  V  ∧  𝐻  ∈  V )  →  ( ( Fun  𝐻  ∧  ( 𝐹  supp   0  )  ⊆  ran  𝐻 )  →  ( 𝐻  “  ( ( 𝐹  ∘  𝐻 )  supp   0  ) )  =  ( 𝐹  supp   0  ) ) ) | 
						
							| 36 | 35 | imp | ⊢ ( ( ( 𝐹  ∈  V  ∧  𝐻  ∈  V )  ∧  ( Fun  𝐻  ∧  ( 𝐹  supp   0  )  ⊆  ran  𝐻 ) )  →  ( 𝐻  “  ( ( 𝐹  ∘  𝐻 )  supp   0  ) )  =  ( 𝐹  supp   0  ) ) | 
						
							| 37 | 34 36 | syl | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  “  ( ( 𝐹  ∘  𝐻 )  supp   0  ) )  =  ( 𝐹  supp   0  ) ) | 
						
							| 38 | 24 37 | eqtrid | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  “  𝑊 )  =  ( 𝐹  supp   0  ) ) | 
						
							| 39 | 38 | f1oeq3d | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( ( 𝐻  ↾  𝑊 ) : 𝑊 –1-1-onto→ ( 𝐻  “  𝑊 )  ↔  ( 𝐻  ↾  𝑊 ) : 𝑊 –1-1-onto→ ( 𝐹  supp   0  ) ) ) | 
						
							| 40 | 23 39 | mpbid | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  ↾  𝑊 ) : 𝑊 –1-1-onto→ ( 𝐹  supp   0  ) ) | 
						
							| 41 |  | isof1o | ⊢ ( 𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 )  →  𝑓 : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ 𝑊 ) | 
						
							| 42 | 41 | ad2antll | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  𝑓 : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ 𝑊 ) | 
						
							| 43 |  | f1oco | ⊢ ( ( ( 𝐻  ↾  𝑊 ) : 𝑊 –1-1-onto→ ( 𝐹  supp   0  )  ∧  𝑓 : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ 𝑊 )  →  ( ( 𝐻  ↾  𝑊 )  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ ( 𝐹  supp   0  ) ) | 
						
							| 44 | 40 42 43 | syl2anc | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( ( 𝐻  ↾  𝑊 )  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ ( 𝐹  supp   0  ) ) | 
						
							| 45 |  | f1of | ⊢ ( 𝑓 : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ 𝑊  →  𝑓 : ( 1 ... ( ♯ ‘ 𝑊 ) ) ⟶ 𝑊 ) | 
						
							| 46 |  | frn | ⊢ ( 𝑓 : ( 1 ... ( ♯ ‘ 𝑊 ) ) ⟶ 𝑊  →  ran  𝑓  ⊆  𝑊 ) | 
						
							| 47 | 42 45 46 | 3syl | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ran  𝑓  ⊆  𝑊 ) | 
						
							| 48 |  | cores | ⊢ ( ran  𝑓  ⊆  𝑊  →  ( ( 𝐻  ↾  𝑊 )  ∘  𝑓 )  =  ( 𝐻  ∘  𝑓 ) ) | 
						
							| 49 |  | f1oeq1 | ⊢ ( ( ( 𝐻  ↾  𝑊 )  ∘  𝑓 )  =  ( 𝐻  ∘  𝑓 )  →  ( ( ( 𝐻  ↾  𝑊 )  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ ( 𝐹  supp   0  )  ↔  ( 𝐻  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ ( 𝐹  supp   0  ) ) ) | 
						
							| 50 | 47 48 49 | 3syl | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( ( ( 𝐻  ↾  𝑊 )  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ ( 𝐹  supp   0  )  ↔  ( 𝐻  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ ( 𝐹  supp   0  ) ) ) | 
						
							| 51 | 44 50 | mpbid | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ ( 𝐹  supp   0  ) ) | 
						
							| 52 |  | fzfi | ⊢ ( 1 ... 𝑀 )  ∈  Fin | 
						
							| 53 |  | ssfi | ⊢ ( ( ( 1 ... 𝑀 )  ∈  Fin  ∧  𝑊  ⊆  ( 1 ... 𝑀 ) )  →  𝑊  ∈  Fin ) | 
						
							| 54 | 52 20 53 | sylancr | ⊢ ( 𝜑  →  𝑊  ∈  Fin ) | 
						
							| 55 | 54 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  𝑊  ∈  Fin ) | 
						
							| 56 | 12 | a1i | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  𝑊  =  ( ( 𝐹  ∘  𝐻 )  supp   0  ) ) | 
						
							| 57 | 56 | imaeq2d | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  “  𝑊 )  =  ( 𝐻  “  ( ( 𝐹  ∘  𝐻 )  supp   0  ) ) ) | 
						
							| 58 | 52 | a1i | ⊢ ( 𝜑  →  ( 1 ... 𝑀 )  ∈  Fin ) | 
						
							| 59 | 17 58 | fexd | ⊢ ( 𝜑  →  𝐻  ∈  V ) | 
						
							| 60 | 25 59 32 | jca31 | ⊢ ( 𝜑  →  ( ( 𝐹  ∈  V  ∧  𝐻  ∈  V )  ∧  ( Fun  𝐻  ∧  ( 𝐹  supp   0  )  ⊆  ran  𝐻 ) ) ) | 
						
							| 61 | 60 | ad2antrr | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( ( 𝐹  ∈  V  ∧  𝐻  ∈  V )  ∧  ( Fun  𝐻  ∧  ( 𝐹  supp   0  )  ⊆  ran  𝐻 ) ) ) | 
						
							| 62 | 61 36 | syl | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  “  ( ( 𝐹  ∘  𝐻 )  supp   0  ) )  =  ( 𝐹  supp   0  ) ) | 
						
							| 63 | 57 62 | eqtrd | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  “  𝑊 )  =  ( 𝐹  supp   0  ) ) | 
						
							| 64 | 63 | f1oeq3d | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( ( 𝐻  ↾  𝑊 ) : 𝑊 –1-1-onto→ ( 𝐻  “  𝑊 )  ↔  ( 𝐻  ↾  𝑊 ) : 𝑊 –1-1-onto→ ( 𝐹  supp   0  ) ) ) | 
						
							| 65 | 23 64 | mpbid | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  ↾  𝑊 ) : 𝑊 –1-1-onto→ ( 𝐹  supp   0  ) ) | 
						
							| 66 | 55 65 | hasheqf1od | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( ♯ ‘ 𝑊 )  =  ( ♯ ‘ ( 𝐹  supp   0  ) ) ) | 
						
							| 67 | 66 | oveq2d | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 1 ... ( ♯ ‘ 𝑊 ) )  =  ( 1 ... ( ♯ ‘ ( 𝐹  supp   0  ) ) ) ) | 
						
							| 68 | 67 | f1oeq2d | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( ( 𝐻  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ 𝑊 ) ) –1-1-onto→ ( 𝐹  supp   0  )  ↔  ( 𝐻  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ ( 𝐹  supp   0  ) ) ) –1-1-onto→ ( 𝐹  supp   0  ) ) ) | 
						
							| 69 | 51 68 | mpbid | ⊢ ( ( ( 𝜑  ∧  𝑊  ≠  ∅ )  ∧  ( ¬  𝐴  ∈  ran  ...  ∧  𝑓  Isom   <  ,   <  ( ( 1 ... ( ♯ ‘ 𝑊 ) ) ,  𝑊 ) ) )  →  ( 𝐻  ∘  𝑓 ) : ( 1 ... ( ♯ ‘ ( 𝐹  supp   0  ) ) ) –1-1-onto→ ( 𝐹  supp   0  ) ) |