| Step | Hyp | Ref | Expression | 
						
							| 1 |  | quart.a | ⊢ ( 𝜑  →  𝐴  ∈  ℂ ) | 
						
							| 2 |  | quart.b | ⊢ ( 𝜑  →  𝐵  ∈  ℂ ) | 
						
							| 3 |  | quart.c | ⊢ ( 𝜑  →  𝐶  ∈  ℂ ) | 
						
							| 4 |  | quart.d | ⊢ ( 𝜑  →  𝐷  ∈  ℂ ) | 
						
							| 5 |  | quart.x | ⊢ ( 𝜑  →  𝑋  ∈  ℂ ) | 
						
							| 6 |  | quart.e | ⊢ ( 𝜑  →  𝐸  =  - ( 𝐴  /  4 ) ) | 
						
							| 7 |  | quart.p | ⊢ ( 𝜑  →  𝑃  =  ( 𝐵  −  ( ( 3  /  8 )  ·  ( 𝐴 ↑ 2 ) ) ) ) | 
						
							| 8 |  | quart.q | ⊢ ( 𝜑  →  𝑄  =  ( ( 𝐶  −  ( ( 𝐴  ·  𝐵 )  /  2 ) )  +  ( ( 𝐴 ↑ 3 )  /  8 ) ) ) | 
						
							| 9 |  | quart.r | ⊢ ( 𝜑  →  𝑅  =  ( ( 𝐷  −  ( ( 𝐶  ·  𝐴 )  /  4 ) )  +  ( ( ( ( 𝐴 ↑ 2 )  ·  𝐵 )  /  ; 1 6 )  −  ( ( 3  /  ; ; 2 5 6 )  ·  ( 𝐴 ↑ 4 ) ) ) ) ) | 
						
							| 10 |  | quart.u | ⊢ ( 𝜑  →  𝑈  =  ( ( 𝑃 ↑ 2 )  +  ( ; 1 2  ·  𝑅 ) ) ) | 
						
							| 11 |  | quart.v | ⊢ ( 𝜑  →  𝑉  =  ( ( - ( 2  ·  ( 𝑃 ↑ 3 ) )  −  ( ; 2 7  ·  ( 𝑄 ↑ 2 ) ) )  +  ( ; 7 2  ·  ( 𝑃  ·  𝑅 ) ) ) ) | 
						
							| 12 |  | quart.w | ⊢ ( 𝜑  →  𝑊  =  ( √ ‘ ( ( 𝑉 ↑ 2 )  −  ( 4  ·  ( 𝑈 ↑ 3 ) ) ) ) ) | 
						
							| 13 |  | quart.s | ⊢ ( 𝜑  →  𝑆  =  ( ( √ ‘ 𝑀 )  /  2 ) ) | 
						
							| 14 |  | quart.m | ⊢ ( 𝜑  →  𝑀  =  - ( ( ( ( 2  ·  𝑃 )  +  𝑇 )  +  ( 𝑈  /  𝑇 ) )  /  3 ) ) | 
						
							| 15 |  | quart.t | ⊢ ( 𝜑  →  𝑇  =  ( ( ( 𝑉  +  𝑊 )  /  2 ) ↑𝑐 ( 1  /  3 ) ) ) | 
						
							| 16 |  | quart.t0 | ⊢ ( 𝜑  →  𝑇  ≠  0 ) | 
						
							| 17 |  | quart.m0 | ⊢ ( 𝜑  →  𝑀  ≠  0 ) | 
						
							| 18 |  | quart.i | ⊢ ( 𝜑  →  𝐼  =  ( √ ‘ ( ( - ( 𝑆 ↑ 2 )  −  ( 𝑃  /  2 ) )  +  ( ( 𝑄  /  4 )  /  𝑆 ) ) ) ) | 
						
							| 19 |  | quart.j | ⊢ ( 𝜑  →  𝐽  =  ( √ ‘ ( ( - ( 𝑆 ↑ 2 )  −  ( 𝑃  /  2 ) )  −  ( ( 𝑄  /  4 )  /  𝑆 ) ) ) ) | 
						
							| 20 | 1 2 3 4 1 6 7 8 9 10 11 12 13 14 15 16 | quartlem3 | ⊢ ( 𝜑  →  ( 𝑆  ∈  ℂ  ∧  𝑀  ∈  ℂ  ∧  𝑇  ∈  ℂ ) ) | 
						
							| 21 | 20 | simp2d | ⊢ ( 𝜑  →  𝑀  ∈  ℂ ) | 
						
							| 22 | 21 | sqrtcld | ⊢ ( 𝜑  →  ( √ ‘ 𝑀 )  ∈  ℂ ) | 
						
							| 23 |  | 2cnd | ⊢ ( 𝜑  →  2  ∈  ℂ ) | 
						
							| 24 | 21 | sqsqrtd | ⊢ ( 𝜑  →  ( ( √ ‘ 𝑀 ) ↑ 2 )  =  𝑀 ) | 
						
							| 25 | 24 17 | eqnetrd | ⊢ ( 𝜑  →  ( ( √ ‘ 𝑀 ) ↑ 2 )  ≠  0 ) | 
						
							| 26 |  | sqne0 | ⊢ ( ( √ ‘ 𝑀 )  ∈  ℂ  →  ( ( ( √ ‘ 𝑀 ) ↑ 2 )  ≠  0  ↔  ( √ ‘ 𝑀 )  ≠  0 ) ) | 
						
							| 27 | 22 26 | syl | ⊢ ( 𝜑  →  ( ( ( √ ‘ 𝑀 ) ↑ 2 )  ≠  0  ↔  ( √ ‘ 𝑀 )  ≠  0 ) ) | 
						
							| 28 | 25 27 | mpbid | ⊢ ( 𝜑  →  ( √ ‘ 𝑀 )  ≠  0 ) | 
						
							| 29 |  | 2ne0 | ⊢ 2  ≠  0 | 
						
							| 30 | 29 | a1i | ⊢ ( 𝜑  →  2  ≠  0 ) | 
						
							| 31 | 22 23 28 30 | divne0d | ⊢ ( 𝜑  →  ( ( √ ‘ 𝑀 )  /  2 )  ≠  0 ) | 
						
							| 32 | 13 31 | eqnetrd | ⊢ ( 𝜑  →  𝑆  ≠  0 ) | 
						
							| 33 | 20 | simp1d | ⊢ ( 𝜑  →  𝑆  ∈  ℂ ) | 
						
							| 34 | 33 | sqcld | ⊢ ( 𝜑  →  ( 𝑆 ↑ 2 )  ∈  ℂ ) | 
						
							| 35 | 34 | negcld | ⊢ ( 𝜑  →  - ( 𝑆 ↑ 2 )  ∈  ℂ ) | 
						
							| 36 | 1 2 3 4 7 8 9 | quart1cl | ⊢ ( 𝜑  →  ( 𝑃  ∈  ℂ  ∧  𝑄  ∈  ℂ  ∧  𝑅  ∈  ℂ ) ) | 
						
							| 37 | 36 | simp1d | ⊢ ( 𝜑  →  𝑃  ∈  ℂ ) | 
						
							| 38 | 37 | halfcld | ⊢ ( 𝜑  →  ( 𝑃  /  2 )  ∈  ℂ ) | 
						
							| 39 | 35 38 | subcld | ⊢ ( 𝜑  →  ( - ( 𝑆 ↑ 2 )  −  ( 𝑃  /  2 ) )  ∈  ℂ ) | 
						
							| 40 | 36 | simp2d | ⊢ ( 𝜑  →  𝑄  ∈  ℂ ) | 
						
							| 41 |  | 4cn | ⊢ 4  ∈  ℂ | 
						
							| 42 | 41 | a1i | ⊢ ( 𝜑  →  4  ∈  ℂ ) | 
						
							| 43 |  | 4ne0 | ⊢ 4  ≠  0 | 
						
							| 44 | 43 | a1i | ⊢ ( 𝜑  →  4  ≠  0 ) | 
						
							| 45 | 40 42 44 | divcld | ⊢ ( 𝜑  →  ( 𝑄  /  4 )  ∈  ℂ ) | 
						
							| 46 | 45 33 32 | divcld | ⊢ ( 𝜑  →  ( ( 𝑄  /  4 )  /  𝑆 )  ∈  ℂ ) | 
						
							| 47 | 39 46 | addcld | ⊢ ( 𝜑  →  ( ( - ( 𝑆 ↑ 2 )  −  ( 𝑃  /  2 ) )  +  ( ( 𝑄  /  4 )  /  𝑆 ) )  ∈  ℂ ) | 
						
							| 48 | 47 | sqrtcld | ⊢ ( 𝜑  →  ( √ ‘ ( ( - ( 𝑆 ↑ 2 )  −  ( 𝑃  /  2 ) )  +  ( ( 𝑄  /  4 )  /  𝑆 ) ) )  ∈  ℂ ) | 
						
							| 49 | 18 48 | eqeltrd | ⊢ ( 𝜑  →  𝐼  ∈  ℂ ) | 
						
							| 50 | 39 46 | subcld | ⊢ ( 𝜑  →  ( ( - ( 𝑆 ↑ 2 )  −  ( 𝑃  /  2 ) )  −  ( ( 𝑄  /  4 )  /  𝑆 ) )  ∈  ℂ ) | 
						
							| 51 | 50 | sqrtcld | ⊢ ( 𝜑  →  ( √ ‘ ( ( - ( 𝑆 ↑ 2 )  −  ( 𝑃  /  2 ) )  −  ( ( 𝑄  /  4 )  /  𝑆 ) ) )  ∈  ℂ ) | 
						
							| 52 | 19 51 | eqeltrd | ⊢ ( 𝜑  →  𝐽  ∈  ℂ ) | 
						
							| 53 | 32 49 52 | 3jca | ⊢ ( 𝜑  →  ( 𝑆  ≠  0  ∧  𝐼  ∈  ℂ  ∧  𝐽  ∈  ℂ ) ) |