| Step | Hyp | Ref | Expression | 
						
							| 1 |  | prodfn0.1 | ⊢ ( 𝜑  →  𝑁  ∈  ( ℤ≥ ‘ 𝑀 ) ) | 
						
							| 2 |  | prodfn0.2 | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  →  ( 𝐹 ‘ 𝑘 )  ∈  ℂ ) | 
						
							| 3 |  | prodfn0.3 | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  →  ( 𝐹 ‘ 𝑘 )  ≠  0 ) | 
						
							| 4 |  | prodfrec.4 | ⊢ ( ( 𝜑  ∧  𝑘  ∈  ( 𝑀 ... 𝑁 ) )  →  ( 𝐺 ‘ 𝑘 )  =  ( 1  /  ( 𝐹 ‘ 𝑘 ) ) ) | 
						
							| 5 |  | eluzfz2 | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑀 )  →  𝑁  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 6 | 1 5 | syl | ⊢ ( 𝜑  →  𝑁  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 7 |  | fveq2 | ⊢ ( 𝑚  =  𝑀  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑀 ) ) | 
						
							| 8 |  | fveq2 | ⊢ ( 𝑚  =  𝑀  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 )  =  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑀 ) ) | 
						
							| 9 | 8 | oveq2d | ⊢ ( 𝑚  =  𝑀  →  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑀 ) ) ) | 
						
							| 10 | 7 9 | eqeq12d | ⊢ ( 𝑚  =  𝑀  →  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) )  ↔  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑀 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑀 ) ) ) ) | 
						
							| 11 | 10 | imbi2d | ⊢ ( 𝑚  =  𝑀  →  ( ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) ) )  ↔  ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑀 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑀 ) ) ) ) ) | 
						
							| 12 |  | fveq2 | ⊢ ( 𝑚  =  𝑛  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 ) ) | 
						
							| 13 |  | fveq2 | ⊢ ( 𝑚  =  𝑛  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 )  =  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) | 
						
							| 14 | 13 | oveq2d | ⊢ ( 𝑚  =  𝑛  →  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) ) | 
						
							| 15 | 12 14 | eqeq12d | ⊢ ( 𝑚  =  𝑛  →  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) )  ↔  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) ) ) | 
						
							| 16 | 15 | imbi2d | ⊢ ( 𝑚  =  𝑛  →  ( ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) ) )  ↔  ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) ) ) ) | 
						
							| 17 |  | fveq2 | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) ) ) | 
						
							| 18 |  | fveq2 | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 )  =  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) ) | 
						
							| 19 | 18 | oveq2d | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 20 | 17 19 | eqeq12d | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) )  ↔  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 21 | 20 | imbi2d | ⊢ ( 𝑚  =  ( 𝑛  +  1 )  →  ( ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) ) )  ↔  ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) ) ) ) ) | 
						
							| 22 |  | fveq2 | ⊢ ( 𝑚  =  𝑁  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑁 ) ) | 
						
							| 23 |  | fveq2 | ⊢ ( 𝑚  =  𝑁  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 )  =  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑁 ) ) | 
						
							| 24 | 23 | oveq2d | ⊢ ( 𝑚  =  𝑁  →  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑁 ) ) ) | 
						
							| 25 | 22 24 | eqeq12d | ⊢ ( 𝑚  =  𝑁  →  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) )  ↔  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑁 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑁 ) ) ) ) | 
						
							| 26 | 25 | imbi2d | ⊢ ( 𝑚  =  𝑁  →  ( ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑚 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑚 ) ) )  ↔  ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑁 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑁 ) ) ) ) ) | 
						
							| 27 |  | eluzfz1 | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑀 )  →  𝑀  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 28 | 1 27 | syl | ⊢ ( 𝜑  →  𝑀  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 29 |  | fveq2 | ⊢ ( 𝑘  =  𝑀  →  ( 𝐺 ‘ 𝑘 )  =  ( 𝐺 ‘ 𝑀 ) ) | 
						
							| 30 |  | fveq2 | ⊢ ( 𝑘  =  𝑀  →  ( 𝐹 ‘ 𝑘 )  =  ( 𝐹 ‘ 𝑀 ) ) | 
						
							| 31 | 30 | oveq2d | ⊢ ( 𝑘  =  𝑀  →  ( 1  /  ( 𝐹 ‘ 𝑘 ) )  =  ( 1  /  ( 𝐹 ‘ 𝑀 ) ) ) | 
						
							| 32 | 29 31 | eqeq12d | ⊢ ( 𝑘  =  𝑀  →  ( ( 𝐺 ‘ 𝑘 )  =  ( 1  /  ( 𝐹 ‘ 𝑘 ) )  ↔  ( 𝐺 ‘ 𝑀 )  =  ( 1  /  ( 𝐹 ‘ 𝑀 ) ) ) ) | 
						
							| 33 | 32 | imbi2d | ⊢ ( 𝑘  =  𝑀  →  ( ( 𝜑  →  ( 𝐺 ‘ 𝑘 )  =  ( 1  /  ( 𝐹 ‘ 𝑘 ) ) )  ↔  ( 𝜑  →  ( 𝐺 ‘ 𝑀 )  =  ( 1  /  ( 𝐹 ‘ 𝑀 ) ) ) ) ) | 
						
							| 34 | 4 | expcom | ⊢ ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝜑  →  ( 𝐺 ‘ 𝑘 )  =  ( 1  /  ( 𝐹 ‘ 𝑘 ) ) ) ) | 
						
							| 35 | 33 34 | vtoclga | ⊢ ( 𝑀  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝜑  →  ( 𝐺 ‘ 𝑀 )  =  ( 1  /  ( 𝐹 ‘ 𝑀 ) ) ) ) | 
						
							| 36 | 28 35 | mpcom | ⊢ ( 𝜑  →  ( 𝐺 ‘ 𝑀 )  =  ( 1  /  ( 𝐹 ‘ 𝑀 ) ) ) | 
						
							| 37 |  | eluzel2 | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑀 )  →  𝑀  ∈  ℤ ) | 
						
							| 38 | 1 37 | syl | ⊢ ( 𝜑  →  𝑀  ∈  ℤ ) | 
						
							| 39 |  | seq1 | ⊢ ( 𝑀  ∈  ℤ  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑀 )  =  ( 𝐺 ‘ 𝑀 ) ) | 
						
							| 40 | 38 39 | syl | ⊢ ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑀 )  =  ( 𝐺 ‘ 𝑀 ) ) | 
						
							| 41 |  | seq1 | ⊢ ( 𝑀  ∈  ℤ  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑀 )  =  ( 𝐹 ‘ 𝑀 ) ) | 
						
							| 42 | 38 41 | syl | ⊢ ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑀 )  =  ( 𝐹 ‘ 𝑀 ) ) | 
						
							| 43 | 42 | oveq2d | ⊢ ( 𝜑  →  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑀 ) )  =  ( 1  /  ( 𝐹 ‘ 𝑀 ) ) ) | 
						
							| 44 | 36 40 43 | 3eqtr4d | ⊢ ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑀 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑀 ) ) ) | 
						
							| 45 | 44 | a1i | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑀 )  →  ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑀 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑀 ) ) ) ) | 
						
							| 46 |  | oveq1 | ⊢ ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  →  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) )  =  ( ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 47 | 46 | 3ad2ant3 | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 )  ∧  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) )  →  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) )  =  ( ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 48 |  | fzofzp1 | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( 𝑛  +  1 )  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 49 |  | fveq2 | ⊢ ( 𝑘  =  ( 𝑛  +  1 )  →  ( 𝐺 ‘ 𝑘 )  =  ( 𝐺 ‘ ( 𝑛  +  1 ) ) ) | 
						
							| 50 |  | fveq2 | ⊢ ( 𝑘  =  ( 𝑛  +  1 )  →  ( 𝐹 ‘ 𝑘 )  =  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) | 
						
							| 51 | 50 | oveq2d | ⊢ ( 𝑘  =  ( 𝑛  +  1 )  →  ( 1  /  ( 𝐹 ‘ 𝑘 ) )  =  ( 1  /  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 52 | 49 51 | eqeq12d | ⊢ ( 𝑘  =  ( 𝑛  +  1 )  →  ( ( 𝐺 ‘ 𝑘 )  =  ( 1  /  ( 𝐹 ‘ 𝑘 ) )  ↔  ( 𝐺 ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 53 | 52 | imbi2d | ⊢ ( 𝑘  =  ( 𝑛  +  1 )  →  ( ( 𝜑  →  ( 𝐺 ‘ 𝑘 )  =  ( 1  /  ( 𝐹 ‘ 𝑘 ) ) )  ↔  ( 𝜑  →  ( 𝐺 ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) ) | 
						
							| 54 | 53 34 | vtoclga | ⊢ ( ( 𝑛  +  1 )  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝜑  →  ( 𝐺 ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 55 | 48 54 | syl | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( 𝜑  →  ( 𝐺 ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 56 | 55 | impcom | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  ( 𝐺 ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 57 | 56 | oveq2d | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  ( ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) )  =  ( ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  ·  ( 1  /  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 58 |  | 1cnd | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  1  ∈  ℂ ) | 
						
							| 59 |  | elfzouz | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  𝑛  ∈  ( ℤ≥ ‘ 𝑀 ) ) | 
						
							| 60 | 59 | adantl | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  𝑛  ∈  ( ℤ≥ ‘ 𝑀 ) ) | 
						
							| 61 |  | elfzouz2 | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  𝑁  ∈  ( ℤ≥ ‘ 𝑛 ) ) | 
						
							| 62 |  | fzss2 | ⊢ ( 𝑁  ∈  ( ℤ≥ ‘ 𝑛 )  →  ( 𝑀 ... 𝑛 )  ⊆  ( 𝑀 ... 𝑁 ) ) | 
						
							| 63 | 61 62 | syl | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( 𝑀 ... 𝑛 )  ⊆  ( 𝑀 ... 𝑁 ) ) | 
						
							| 64 | 63 | sselda | ⊢ ( ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  ∧  𝑘  ∈  ( 𝑀 ... 𝑛 ) )  →  𝑘  ∈  ( 𝑀 ... 𝑁 ) ) | 
						
							| 65 | 64 2 | sylan2 | ⊢ ( ( 𝜑  ∧  ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  ∧  𝑘  ∈  ( 𝑀 ... 𝑛 ) ) )  →  ( 𝐹 ‘ 𝑘 )  ∈  ℂ ) | 
						
							| 66 | 65 | anassrs | ⊢ ( ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  ∧  𝑘  ∈  ( 𝑀 ... 𝑛 ) )  →  ( 𝐹 ‘ 𝑘 )  ∈  ℂ ) | 
						
							| 67 |  | mulcl | ⊢ ( ( 𝑘  ∈  ℂ  ∧  𝑥  ∈  ℂ )  →  ( 𝑘  ·  𝑥 )  ∈  ℂ ) | 
						
							| 68 | 67 | adantl | ⊢ ( ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  ∧  ( 𝑘  ∈  ℂ  ∧  𝑥  ∈  ℂ ) )  →  ( 𝑘  ·  𝑥 )  ∈  ℂ ) | 
						
							| 69 | 60 66 68 | seqcl | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ∈  ℂ ) | 
						
							| 70 | 50 | eleq1d | ⊢ ( 𝑘  =  ( 𝑛  +  1 )  →  ( ( 𝐹 ‘ 𝑘 )  ∈  ℂ  ↔  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ∈  ℂ ) ) | 
						
							| 71 | 70 | imbi2d | ⊢ ( 𝑘  =  ( 𝑛  +  1 )  →  ( ( 𝜑  →  ( 𝐹 ‘ 𝑘 )  ∈  ℂ )  ↔  ( 𝜑  →  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ∈  ℂ ) ) ) | 
						
							| 72 | 2 | expcom | ⊢ ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝜑  →  ( 𝐹 ‘ 𝑘 )  ∈  ℂ ) ) | 
						
							| 73 | 71 72 | vtoclga | ⊢ ( ( 𝑛  +  1 )  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝜑  →  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ∈  ℂ ) ) | 
						
							| 74 | 48 73 | syl | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( 𝜑  →  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ∈  ℂ ) ) | 
						
							| 75 | 74 | impcom | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ∈  ℂ ) | 
						
							| 76 | 64 3 | sylan2 | ⊢ ( ( 𝜑  ∧  ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  ∧  𝑘  ∈  ( 𝑀 ... 𝑛 ) ) )  →  ( 𝐹 ‘ 𝑘 )  ≠  0 ) | 
						
							| 77 | 76 | anassrs | ⊢ ( ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  ∧  𝑘  ∈  ( 𝑀 ... 𝑛 ) )  →  ( 𝐹 ‘ 𝑘 )  ≠  0 ) | 
						
							| 78 | 60 66 77 | prodfn0 | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ≠  0 ) | 
						
							| 79 | 50 | neeq1d | ⊢ ( 𝑘  =  ( 𝑛  +  1 )  →  ( ( 𝐹 ‘ 𝑘 )  ≠  0  ↔  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ≠  0 ) ) | 
						
							| 80 | 79 | imbi2d | ⊢ ( 𝑘  =  ( 𝑛  +  1 )  →  ( ( 𝜑  →  ( 𝐹 ‘ 𝑘 )  ≠  0 )  ↔  ( 𝜑  →  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ≠  0 ) ) ) | 
						
							| 81 | 3 | expcom | ⊢ ( 𝑘  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝜑  →  ( 𝐹 ‘ 𝑘 )  ≠  0 ) ) | 
						
							| 82 | 80 81 | vtoclga | ⊢ ( ( 𝑛  +  1 )  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝜑  →  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ≠  0 ) ) | 
						
							| 83 | 48 82 | syl | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( 𝜑  →  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ≠  0 ) ) | 
						
							| 84 | 83 | impcom | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  ( 𝐹 ‘ ( 𝑛  +  1 ) )  ≠  0 ) | 
						
							| 85 | 58 69 58 75 78 84 | divmuldivd | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  ( ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  ·  ( 1  /  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) )  =  ( ( 1  ·  1 )  /  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 86 |  | 1t1e1 | ⊢ ( 1  ·  1 )  =  1 | 
						
							| 87 | 86 | oveq1i | ⊢ ( ( 1  ·  1 )  /  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) )  =  ( 1  /  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 88 | 85 87 | eqtrdi | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  ( ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  ·  ( 1  /  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) )  =  ( 1  /  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 89 | 57 88 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 ) )  →  ( ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) )  =  ( 1  /  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 90 | 89 | 3adant3 | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 )  ∧  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) )  →  ( ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) )  =  ( 1  /  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 91 | 47 90 | eqtrd | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 )  ∧  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) )  →  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) )  =  ( 1  /  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 92 |  | seqp1 | ⊢ ( 𝑛  ∈  ( ℤ≥ ‘ 𝑀 )  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) )  =  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 93 | 59 92 | syl | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) )  =  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 94 | 93 | 3ad2ant2 | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 )  ∧  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) )  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) )  =  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  ·  ( 𝐺 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 95 |  | seqp1 | ⊢ ( 𝑛  ∈  ( ℤ≥ ‘ 𝑀 )  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) )  =  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 96 | 59 95 | syl | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) )  =  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 97 | 96 | oveq2d | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) )  =  ( 1  /  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 98 | 97 | 3ad2ant2 | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 )  ∧  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) )  →  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) )  =  ( 1  /  ( ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 )  ·  ( 𝐹 ‘ ( 𝑛  +  1 ) ) ) ) ) | 
						
							| 99 | 91 94 98 | 3eqtr4d | ⊢ ( ( 𝜑  ∧  𝑛  ∈  ( 𝑀 ..^ 𝑁 )  ∧  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) )  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) ) ) | 
						
							| 100 | 99 | 3exp | ⊢ ( 𝜑  →  ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) ) ) ) ) | 
						
							| 101 | 100 | com12 | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( 𝜑  →  ( ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) )  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) ) ) ) ) | 
						
							| 102 | 101 | a2d | ⊢ ( 𝑛  ∈  ( 𝑀 ..^ 𝑁 )  →  ( ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑛 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑛 ) ) )  →  ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ ( 𝑛  +  1 ) )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ ( 𝑛  +  1 ) ) ) ) ) ) | 
						
							| 103 | 11 16 21 26 45 102 | fzind2 | ⊢ ( 𝑁  ∈  ( 𝑀 ... 𝑁 )  →  ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑁 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑁 ) ) ) ) | 
						
							| 104 | 6 103 | mpcom | ⊢ ( 𝜑  →  ( seq 𝑀 (  ·  ,  𝐺 ) ‘ 𝑁 )  =  ( 1  /  ( seq 𝑀 (  ·  ,  𝐹 ) ‘ 𝑁 ) ) ) |