| Step | Hyp | Ref | Expression | 
						
							| 1 |  | ovex | ⊢ ( 𝐴  mod  8 )  ∈  V | 
						
							| 2 | 1 | elpr | ⊢ ( ( 𝐴  mod  8 )  ∈  { 3 ,  5 }  ↔  ( ( 𝐴  mod  8 )  =  3  ∨  ( 𝐴  mod  8 )  =  5 ) ) | 
						
							| 3 |  | ovex | ⊢ ( 𝐵  mod  8 )  ∈  V | 
						
							| 4 | 3 | elpr | ⊢ ( ( 𝐵  mod  8 )  ∈  { 3 ,  5 }  ↔  ( ( 𝐵  mod  8 )  =  3  ∨  ( 𝐵  mod  8 )  =  5 ) ) | 
						
							| 5 | 2 4 | anbi12i | ⊢ ( ( ( 𝐴  mod  8 )  ∈  { 3 ,  5 }  ∧  ( 𝐵  mod  8 )  ∈  { 3 ,  5 } )  ↔  ( ( ( 𝐴  mod  8 )  =  3  ∨  ( 𝐴  mod  8 )  =  5 )  ∧  ( ( 𝐵  mod  8 )  =  3  ∨  ( 𝐵  mod  8 )  =  5 ) ) ) | 
						
							| 6 |  | simpll | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  𝐴  ∈  ℤ ) | 
						
							| 7 |  | 3z | ⊢ 3  ∈  ℤ | 
						
							| 8 | 7 | a1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  3  ∈  ℤ ) | 
						
							| 9 |  | simplr | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  𝐵  ∈  ℤ ) | 
						
							| 10 |  | 8re | ⊢ 8  ∈  ℝ | 
						
							| 11 |  | 8pos | ⊢ 0  <  8 | 
						
							| 12 | 10 11 | elrpii | ⊢ 8  ∈  ℝ+ | 
						
							| 13 | 12 | a1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  8  ∈  ℝ+ ) | 
						
							| 14 |  | simprl | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( 𝐴  mod  8 )  =  3 ) | 
						
							| 15 |  | lgsdir2lem1 | ⊢ ( ( ( 1  mod  8 )  =  1  ∧  ( - 1  mod  8 )  =  7 )  ∧  ( ( 3  mod  8 )  =  3  ∧  ( - 3  mod  8 )  =  5 ) ) | 
						
							| 16 | 15 | simpri | ⊢ ( ( 3  mod  8 )  =  3  ∧  ( - 3  mod  8 )  =  5 ) | 
						
							| 17 | 16 | simpli | ⊢ ( 3  mod  8 )  =  3 | 
						
							| 18 | 14 17 | eqtr4di | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( 𝐴  mod  8 )  =  ( 3  mod  8 ) ) | 
						
							| 19 |  | simprr | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( 𝐵  mod  8 )  =  3 ) | 
						
							| 20 | 19 17 | eqtr4di | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( 𝐵  mod  8 )  =  ( 3  mod  8 ) ) | 
						
							| 21 | 6 8 9 8 13 18 20 | modmul12d | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 ) ) | 
						
							| 22 | 21 | orcd | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) | 
						
							| 23 | 22 | ex | ⊢ ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  →  ( ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  3 )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) ) | 
						
							| 24 |  | simpll | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  𝐴  ∈  ℤ ) | 
						
							| 25 |  | znegcl | ⊢ ( 3  ∈  ℤ  →  - 3  ∈  ℤ ) | 
						
							| 26 | 7 25 | mp1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  - 3  ∈  ℤ ) | 
						
							| 27 |  | simplr | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  𝐵  ∈  ℤ ) | 
						
							| 28 | 7 | a1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  3  ∈  ℤ ) | 
						
							| 29 | 12 | a1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  8  ∈  ℝ+ ) | 
						
							| 30 |  | simprl | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( 𝐴  mod  8 )  =  5 ) | 
						
							| 31 | 16 | simpri | ⊢ ( - 3  mod  8 )  =  5 | 
						
							| 32 | 30 31 | eqtr4di | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( 𝐴  mod  8 )  =  ( - 3  mod  8 ) ) | 
						
							| 33 |  | simprr | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( 𝐵  mod  8 )  =  3 ) | 
						
							| 34 | 33 17 | eqtr4di | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( 𝐵  mod  8 )  =  ( 3  mod  8 ) ) | 
						
							| 35 | 24 26 27 28 29 32 34 | modmul12d | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( - 3  ·  3 )  mod  8 ) ) | 
						
							| 36 |  | 3cn | ⊢ 3  ∈  ℂ | 
						
							| 37 | 36 36 | mulneg1i | ⊢ ( - 3  ·  3 )  =  - ( 3  ·  3 ) | 
						
							| 38 | 37 | oveq1i | ⊢ ( ( - 3  ·  3 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) | 
						
							| 39 | 35 38 | eqtrdi | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) | 
						
							| 40 | 39 | olcd | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 ) )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) | 
						
							| 41 | 40 | ex | ⊢ ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  →  ( ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  3 )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) ) | 
						
							| 42 |  | simpll | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  𝐴  ∈  ℤ ) | 
						
							| 43 | 7 | a1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  3  ∈  ℤ ) | 
						
							| 44 |  | simplr | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  𝐵  ∈  ℤ ) | 
						
							| 45 | 7 25 | mp1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  - 3  ∈  ℤ ) | 
						
							| 46 | 12 | a1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  8  ∈  ℝ+ ) | 
						
							| 47 |  | simprl | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( 𝐴  mod  8 )  =  3 ) | 
						
							| 48 | 47 17 | eqtr4di | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( 𝐴  mod  8 )  =  ( 3  mod  8 ) ) | 
						
							| 49 |  | simprr | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( 𝐵  mod  8 )  =  5 ) | 
						
							| 50 | 49 31 | eqtr4di | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( 𝐵  mod  8 )  =  ( - 3  mod  8 ) ) | 
						
							| 51 | 42 43 44 45 46 48 50 | modmul12d | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  - 3 )  mod  8 ) ) | 
						
							| 52 | 36 36 | mulneg2i | ⊢ ( 3  ·  - 3 )  =  - ( 3  ·  3 ) | 
						
							| 53 | 52 | oveq1i | ⊢ ( ( 3  ·  - 3 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) | 
						
							| 54 | 51 53 | eqtrdi | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) | 
						
							| 55 | 54 | olcd | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) | 
						
							| 56 | 55 | ex | ⊢ ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  →  ( ( ( 𝐴  mod  8 )  =  3  ∧  ( 𝐵  mod  8 )  =  5 )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) ) | 
						
							| 57 |  | simpll | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  𝐴  ∈  ℤ ) | 
						
							| 58 | 7 25 | mp1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  - 3  ∈  ℤ ) | 
						
							| 59 |  | simplr | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  𝐵  ∈  ℤ ) | 
						
							| 60 | 12 | a1i | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  8  ∈  ℝ+ ) | 
						
							| 61 |  | simprl | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( 𝐴  mod  8 )  =  5 ) | 
						
							| 62 | 61 31 | eqtr4di | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( 𝐴  mod  8 )  =  ( - 3  mod  8 ) ) | 
						
							| 63 |  | simprr | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( 𝐵  mod  8 )  =  5 ) | 
						
							| 64 | 63 31 | eqtr4di | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( 𝐵  mod  8 )  =  ( - 3  mod  8 ) ) | 
						
							| 65 | 57 58 59 58 60 62 64 | modmul12d | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( - 3  ·  - 3 )  mod  8 ) ) | 
						
							| 66 | 36 36 | mul2negi | ⊢ ( - 3  ·  - 3 )  =  ( 3  ·  3 ) | 
						
							| 67 | 66 | oveq1i | ⊢ ( ( - 3  ·  - 3 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 ) | 
						
							| 68 | 65 67 | eqtrdi | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 ) ) | 
						
							| 69 | 68 | orcd | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 ) )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) | 
						
							| 70 | 69 | ex | ⊢ ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  →  ( ( ( 𝐴  mod  8 )  =  5  ∧  ( 𝐵  mod  8 )  =  5 )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) ) | 
						
							| 71 | 23 41 56 70 | ccased | ⊢ ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  →  ( ( ( ( 𝐴  mod  8 )  =  3  ∨  ( 𝐴  mod  8 )  =  5 )  ∧  ( ( 𝐵  mod  8 )  =  3  ∨  ( 𝐵  mod  8 )  =  5 ) )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) ) | 
						
							| 72 | 5 71 | biimtrid | ⊢ ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  →  ( ( ( 𝐴  mod  8 )  ∈  { 3 ,  5 }  ∧  ( 𝐵  mod  8 )  ∈  { 3 ,  5 } )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) ) | 
						
							| 73 | 72 | imp | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  ∈  { 3 ,  5 }  ∧  ( 𝐵  mod  8 )  ∈  { 3 ,  5 } ) )  →  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) | 
						
							| 74 |  | ovex | ⊢ ( ( 𝐴  ·  𝐵 )  mod  8 )  ∈  V | 
						
							| 75 | 74 | elpr | ⊢ ( ( ( 𝐴  ·  𝐵 )  mod  8 )  ∈  { ( ( 3  ·  3 )  mod  8 ) ,  ( - ( 3  ·  3 )  mod  8 ) }  ↔  ( ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( ( 3  ·  3 )  mod  8 )  ∨  ( ( 𝐴  ·  𝐵 )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) ) ) | 
						
							| 76 | 73 75 | sylibr | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  ∈  { 3 ,  5 }  ∧  ( 𝐵  mod  8 )  ∈  { 3 ,  5 } ) )  →  ( ( 𝐴  ·  𝐵 )  mod  8 )  ∈  { ( ( 3  ·  3 )  mod  8 ) ,  ( - ( 3  ·  3 )  mod  8 ) } ) | 
						
							| 77 |  | df-9 | ⊢ 9  =  ( 8  +  1 ) | 
						
							| 78 |  | 8cn | ⊢ 8  ∈  ℂ | 
						
							| 79 |  | ax-1cn | ⊢ 1  ∈  ℂ | 
						
							| 80 | 78 79 | addcomi | ⊢ ( 8  +  1 )  =  ( 1  +  8 ) | 
						
							| 81 | 77 80 | eqtri | ⊢ 9  =  ( 1  +  8 ) | 
						
							| 82 |  | 3t3e9 | ⊢ ( 3  ·  3 )  =  9 | 
						
							| 83 | 78 | mullidi | ⊢ ( 1  ·  8 )  =  8 | 
						
							| 84 | 83 | oveq2i | ⊢ ( 1  +  ( 1  ·  8 ) )  =  ( 1  +  8 ) | 
						
							| 85 | 81 82 84 | 3eqtr4i | ⊢ ( 3  ·  3 )  =  ( 1  +  ( 1  ·  8 ) ) | 
						
							| 86 | 85 | oveq1i | ⊢ ( ( 3  ·  3 )  mod  8 )  =  ( ( 1  +  ( 1  ·  8 ) )  mod  8 ) | 
						
							| 87 |  | 1re | ⊢ 1  ∈  ℝ | 
						
							| 88 |  | 1z | ⊢ 1  ∈  ℤ | 
						
							| 89 |  | modcyc | ⊢ ( ( 1  ∈  ℝ  ∧  8  ∈  ℝ+  ∧  1  ∈  ℤ )  →  ( ( 1  +  ( 1  ·  8 ) )  mod  8 )  =  ( 1  mod  8 ) ) | 
						
							| 90 | 87 12 88 89 | mp3an | ⊢ ( ( 1  +  ( 1  ·  8 ) )  mod  8 )  =  ( 1  mod  8 ) | 
						
							| 91 | 86 90 | eqtri | ⊢ ( ( 3  ·  3 )  mod  8 )  =  ( 1  mod  8 ) | 
						
							| 92 | 15 | simpli | ⊢ ( ( 1  mod  8 )  =  1  ∧  ( - 1  mod  8 )  =  7 ) | 
						
							| 93 | 92 | simpli | ⊢ ( 1  mod  8 )  =  1 | 
						
							| 94 | 91 93 | eqtri | ⊢ ( ( 3  ·  3 )  mod  8 )  =  1 | 
						
							| 95 |  | znegcl | ⊢ ( 1  ∈  ℤ  →  - 1  ∈  ℤ ) | 
						
							| 96 | 88 95 | mp1i | ⊢ ( ⊤  →  - 1  ∈  ℤ ) | 
						
							| 97 |  | 3nn | ⊢ 3  ∈  ℕ | 
						
							| 98 | 97 97 | nnmulcli | ⊢ ( 3  ·  3 )  ∈  ℕ | 
						
							| 99 | 98 | nnzi | ⊢ ( 3  ·  3 )  ∈  ℤ | 
						
							| 100 | 99 | a1i | ⊢ ( ⊤  →  ( 3  ·  3 )  ∈  ℤ ) | 
						
							| 101 | 88 | a1i | ⊢ ( ⊤  →  1  ∈  ℤ ) | 
						
							| 102 | 12 | a1i | ⊢ ( ⊤  →  8  ∈  ℝ+ ) | 
						
							| 103 |  | eqidd | ⊢ ( ⊤  →  ( - 1  mod  8 )  =  ( - 1  mod  8 ) ) | 
						
							| 104 | 91 | a1i | ⊢ ( ⊤  →  ( ( 3  ·  3 )  mod  8 )  =  ( 1  mod  8 ) ) | 
						
							| 105 | 96 96 100 101 102 103 104 | modmul12d | ⊢ ( ⊤  →  ( ( - 1  ·  ( 3  ·  3 ) )  mod  8 )  =  ( ( - 1  ·  1 )  mod  8 ) ) | 
						
							| 106 | 105 | mptru | ⊢ ( ( - 1  ·  ( 3  ·  3 ) )  mod  8 )  =  ( ( - 1  ·  1 )  mod  8 ) | 
						
							| 107 | 36 36 | mulcli | ⊢ ( 3  ·  3 )  ∈  ℂ | 
						
							| 108 | 107 | mulm1i | ⊢ ( - 1  ·  ( 3  ·  3 ) )  =  - ( 3  ·  3 ) | 
						
							| 109 | 108 | oveq1i | ⊢ ( ( - 1  ·  ( 3  ·  3 ) )  mod  8 )  =  ( - ( 3  ·  3 )  mod  8 ) | 
						
							| 110 | 79 | mulm1i | ⊢ ( - 1  ·  1 )  =  - 1 | 
						
							| 111 | 110 | oveq1i | ⊢ ( ( - 1  ·  1 )  mod  8 )  =  ( - 1  mod  8 ) | 
						
							| 112 | 106 109 111 | 3eqtr3i | ⊢ ( - ( 3  ·  3 )  mod  8 )  =  ( - 1  mod  8 ) | 
						
							| 113 | 92 | simpri | ⊢ ( - 1  mod  8 )  =  7 | 
						
							| 114 | 112 113 | eqtri | ⊢ ( - ( 3  ·  3 )  mod  8 )  =  7 | 
						
							| 115 | 94 114 | preq12i | ⊢ { ( ( 3  ·  3 )  mod  8 ) ,  ( - ( 3  ·  3 )  mod  8 ) }  =  { 1 ,  7 } | 
						
							| 116 | 76 115 | eleqtrdi | ⊢ ( ( ( 𝐴  ∈  ℤ  ∧  𝐵  ∈  ℤ )  ∧  ( ( 𝐴  mod  8 )  ∈  { 3 ,  5 }  ∧  ( 𝐵  mod  8 )  ∈  { 3 ,  5 } ) )  →  ( ( 𝐴  ·  𝐵 )  mod  8 )  ∈  { 1 ,  7 } ) |