| Step | Hyp | Ref | Expression | 
						
							| 1 |  | itscnhlc0yqe.q | ⊢ 𝑄  =  ( ( 𝐴 ↑ 2 )  +  ( 𝐵 ↑ 2 ) ) | 
						
							| 2 |  | itscnhlc0yqe.t | ⊢ 𝑇  =  - ( 2  ·  ( 𝐵  ·  𝐶 ) ) | 
						
							| 3 |  | itscnhlc0yqe.u | ⊢ 𝑈  =  ( ( 𝐶 ↑ 2 )  −  ( ( 𝐴 ↑ 2 )  ·  ( 𝑅 ↑ 2 ) ) ) | 
						
							| 4 |  | itsclc0yqsollem1.d | ⊢ 𝐷  =  ( ( ( 𝑅 ↑ 2 )  ·  𝑄 )  −  ( 𝐶 ↑ 2 ) ) | 
						
							| 5 |  | recn | ⊢ ( 𝐴  ∈  ℝ  →  𝐴  ∈  ℂ ) | 
						
							| 6 |  | recn | ⊢ ( 𝐵  ∈  ℝ  →  𝐵  ∈  ℂ ) | 
						
							| 7 |  | recn | ⊢ ( 𝐶  ∈  ℝ  →  𝐶  ∈  ℂ ) | 
						
							| 8 | 5 6 7 | 3anim123i | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  →  ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈  ℂ ) ) | 
						
							| 9 |  | recn | ⊢ ( 𝑅  ∈  ℝ  →  𝑅  ∈  ℂ ) | 
						
							| 10 | 8 9 | anim12i | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ )  →  ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈  ℂ )  ∧  𝑅  ∈  ℂ ) ) | 
						
							| 11 | 10 | 3adant3 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈  ℂ )  ∧  𝑅  ∈  ℂ ) ) | 
						
							| 12 | 1 2 3 4 | itsclc0yqsollem1 | ⊢ ( ( ( 𝐴  ∈  ℂ  ∧  𝐵  ∈  ℂ  ∧  𝐶  ∈  ℂ )  ∧  𝑅  ∈  ℂ )  →  ( ( 𝑇 ↑ 2 )  −  ( 4  ·  ( 𝑄  ·  𝑈 ) ) )  =  ( ( 4  ·  ( 𝐴 ↑ 2 ) )  ·  𝐷 ) ) | 
						
							| 13 | 11 12 | syl | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( ( 𝑇 ↑ 2 )  −  ( 4  ·  ( 𝑄  ·  𝑈 ) ) )  =  ( ( 4  ·  ( 𝐴 ↑ 2 ) )  ·  𝐷 ) ) | 
						
							| 14 | 13 | fveq2d | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( √ ‘ ( ( 𝑇 ↑ 2 )  −  ( 4  ·  ( 𝑄  ·  𝑈 ) ) ) )  =  ( √ ‘ ( ( 4  ·  ( 𝐴 ↑ 2 ) )  ·  𝐷 ) ) ) | 
						
							| 15 |  | 4re | ⊢ 4  ∈  ℝ | 
						
							| 16 | 15 | a1i | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  4  ∈  ℝ ) | 
						
							| 17 |  | simp1 | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  →  𝐴  ∈  ℝ ) | 
						
							| 18 | 17 | resqcld | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  →  ( 𝐴 ↑ 2 )  ∈  ℝ ) | 
						
							| 19 | 18 | 3ad2ant1 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( 𝐴 ↑ 2 )  ∈  ℝ ) | 
						
							| 20 | 16 19 | remulcld | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( 4  ·  ( 𝐴 ↑ 2 ) )  ∈  ℝ ) | 
						
							| 21 |  | 0re | ⊢ 0  ∈  ℝ | 
						
							| 22 |  | 4pos | ⊢ 0  <  4 | 
						
							| 23 | 21 15 22 | ltleii | ⊢ 0  ≤  4 | 
						
							| 24 | 23 | a1i | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  0  ≤  4 ) | 
						
							| 25 | 17 | sqge0d | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  →  0  ≤  ( 𝐴 ↑ 2 ) ) | 
						
							| 26 | 25 | 3ad2ant1 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  0  ≤  ( 𝐴 ↑ 2 ) ) | 
						
							| 27 | 16 19 24 26 | mulge0d | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  0  ≤  ( 4  ·  ( 𝐴 ↑ 2 ) ) ) | 
						
							| 28 |  | simp2 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  𝑅  ∈  ℝ ) | 
						
							| 29 | 28 | resqcld | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( 𝑅 ↑ 2 )  ∈  ℝ ) | 
						
							| 30 | 1 | resum2sqcl | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ )  →  𝑄  ∈  ℝ ) | 
						
							| 31 | 30 | 3adant3 | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  →  𝑄  ∈  ℝ ) | 
						
							| 32 | 31 | 3ad2ant1 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  𝑄  ∈  ℝ ) | 
						
							| 33 | 29 32 | remulcld | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( ( 𝑅 ↑ 2 )  ·  𝑄 )  ∈  ℝ ) | 
						
							| 34 |  | simp3 | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  →  𝐶  ∈  ℝ ) | 
						
							| 35 | 34 | resqcld | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  →  ( 𝐶 ↑ 2 )  ∈  ℝ ) | 
						
							| 36 | 35 | 3ad2ant1 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( 𝐶 ↑ 2 )  ∈  ℝ ) | 
						
							| 37 | 33 36 | resubcld | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( ( ( 𝑅 ↑ 2 )  ·  𝑄 )  −  ( 𝐶 ↑ 2 ) )  ∈  ℝ ) | 
						
							| 38 | 4 37 | eqeltrid | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  𝐷  ∈  ℝ ) | 
						
							| 39 |  | simp3 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  0  ≤  𝐷 ) | 
						
							| 40 | 20 27 38 39 | sqrtmuld | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( √ ‘ ( ( 4  ·  ( 𝐴 ↑ 2 ) )  ·  𝐷 ) )  =  ( ( √ ‘ ( 4  ·  ( 𝐴 ↑ 2 ) ) )  ·  ( √ ‘ 𝐷 ) ) ) | 
						
							| 41 | 15 23 | pm3.2i | ⊢ ( 4  ∈  ℝ  ∧  0  ≤  4 ) | 
						
							| 42 | 41 | a1i | ⊢ ( 𝐴  ∈  ℝ  →  ( 4  ∈  ℝ  ∧  0  ≤  4 ) ) | 
						
							| 43 |  | resqcl | ⊢ ( 𝐴  ∈  ℝ  →  ( 𝐴 ↑ 2 )  ∈  ℝ ) | 
						
							| 44 |  | sqge0 | ⊢ ( 𝐴  ∈  ℝ  →  0  ≤  ( 𝐴 ↑ 2 ) ) | 
						
							| 45 |  | sqrtmul | ⊢ ( ( ( 4  ∈  ℝ  ∧  0  ≤  4 )  ∧  ( ( 𝐴 ↑ 2 )  ∈  ℝ  ∧  0  ≤  ( 𝐴 ↑ 2 ) ) )  →  ( √ ‘ ( 4  ·  ( 𝐴 ↑ 2 ) ) )  =  ( ( √ ‘ 4 )  ·  ( √ ‘ ( 𝐴 ↑ 2 ) ) ) ) | 
						
							| 46 | 42 43 44 45 | syl12anc | ⊢ ( 𝐴  ∈  ℝ  →  ( √ ‘ ( 4  ·  ( 𝐴 ↑ 2 ) ) )  =  ( ( √ ‘ 4 )  ·  ( √ ‘ ( 𝐴 ↑ 2 ) ) ) ) | 
						
							| 47 | 46 | 3ad2ant1 | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  →  ( √ ‘ ( 4  ·  ( 𝐴 ↑ 2 ) ) )  =  ( ( √ ‘ 4 )  ·  ( √ ‘ ( 𝐴 ↑ 2 ) ) ) ) | 
						
							| 48 | 47 | 3ad2ant1 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( √ ‘ ( 4  ·  ( 𝐴 ↑ 2 ) ) )  =  ( ( √ ‘ 4 )  ·  ( √ ‘ ( 𝐴 ↑ 2 ) ) ) ) | 
						
							| 49 |  | sqrt4 | ⊢ ( √ ‘ 4 )  =  2 | 
						
							| 50 | 49 | a1i | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( √ ‘ 4 )  =  2 ) | 
						
							| 51 |  | absre | ⊢ ( 𝐴  ∈  ℝ  →  ( abs ‘ 𝐴 )  =  ( √ ‘ ( 𝐴 ↑ 2 ) ) ) | 
						
							| 52 | 51 | eqcomd | ⊢ ( 𝐴  ∈  ℝ  →  ( √ ‘ ( 𝐴 ↑ 2 ) )  =  ( abs ‘ 𝐴 ) ) | 
						
							| 53 | 52 | 3ad2ant1 | ⊢ ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  →  ( √ ‘ ( 𝐴 ↑ 2 ) )  =  ( abs ‘ 𝐴 ) ) | 
						
							| 54 | 53 | 3ad2ant1 | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( √ ‘ ( 𝐴 ↑ 2 ) )  =  ( abs ‘ 𝐴 ) ) | 
						
							| 55 | 50 54 | oveq12d | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( ( √ ‘ 4 )  ·  ( √ ‘ ( 𝐴 ↑ 2 ) ) )  =  ( 2  ·  ( abs ‘ 𝐴 ) ) ) | 
						
							| 56 | 48 55 | eqtrd | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( √ ‘ ( 4  ·  ( 𝐴 ↑ 2 ) ) )  =  ( 2  ·  ( abs ‘ 𝐴 ) ) ) | 
						
							| 57 | 56 | oveq1d | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( ( √ ‘ ( 4  ·  ( 𝐴 ↑ 2 ) ) )  ·  ( √ ‘ 𝐷 ) )  =  ( ( 2  ·  ( abs ‘ 𝐴 ) )  ·  ( √ ‘ 𝐷 ) ) ) | 
						
							| 58 | 14 40 57 | 3eqtrd | ⊢ ( ( ( 𝐴  ∈  ℝ  ∧  𝐵  ∈  ℝ  ∧  𝐶  ∈  ℝ )  ∧  𝑅  ∈  ℝ  ∧  0  ≤  𝐷 )  →  ( √ ‘ ( ( 𝑇 ↑ 2 )  −  ( 4  ·  ( 𝑄  ·  𝑈 ) ) ) )  =  ( ( 2  ·  ( abs ‘ 𝐴 ) )  ·  ( √ ‘ 𝐷 ) ) ) |