| Step | Hyp | Ref | Expression | 
						
							| 1 |  | numlt.1 | ⊢ 𝑇  ∈  ℕ | 
						
							| 2 |  | numlt.2 | ⊢ 𝐴  ∈  ℕ0 | 
						
							| 3 |  | numlt.3 | ⊢ 𝐵  ∈  ℕ0 | 
						
							| 4 |  | numltc.3 | ⊢ 𝐶  ∈  ℕ0 | 
						
							| 5 |  | numltc.4 | ⊢ 𝐷  ∈  ℕ0 | 
						
							| 6 |  | numltc.5 | ⊢ 𝐶  <  𝑇 | 
						
							| 7 |  | numltc.6 | ⊢ 𝐴  <  𝐵 | 
						
							| 8 | 1 2 4 1 6 | numlt | ⊢ ( ( 𝑇  ·  𝐴 )  +  𝐶 )  <  ( ( 𝑇  ·  𝐴 )  +  𝑇 ) | 
						
							| 9 | 1 | nnrei | ⊢ 𝑇  ∈  ℝ | 
						
							| 10 | 9 | recni | ⊢ 𝑇  ∈  ℂ | 
						
							| 11 | 2 | nn0rei | ⊢ 𝐴  ∈  ℝ | 
						
							| 12 | 11 | recni | ⊢ 𝐴  ∈  ℂ | 
						
							| 13 |  | ax-1cn | ⊢ 1  ∈  ℂ | 
						
							| 14 | 10 12 13 | adddii | ⊢ ( 𝑇  ·  ( 𝐴  +  1 ) )  =  ( ( 𝑇  ·  𝐴 )  +  ( 𝑇  ·  1 ) ) | 
						
							| 15 | 10 | mulridi | ⊢ ( 𝑇  ·  1 )  =  𝑇 | 
						
							| 16 | 15 | oveq2i | ⊢ ( ( 𝑇  ·  𝐴 )  +  ( 𝑇  ·  1 ) )  =  ( ( 𝑇  ·  𝐴 )  +  𝑇 ) | 
						
							| 17 | 14 16 | eqtri | ⊢ ( 𝑇  ·  ( 𝐴  +  1 ) )  =  ( ( 𝑇  ·  𝐴 )  +  𝑇 ) | 
						
							| 18 | 8 17 | breqtrri | ⊢ ( ( 𝑇  ·  𝐴 )  +  𝐶 )  <  ( 𝑇  ·  ( 𝐴  +  1 ) ) | 
						
							| 19 |  | nn0ltp1le | ⊢ ( ( 𝐴  ∈  ℕ0  ∧  𝐵  ∈  ℕ0 )  →  ( 𝐴  <  𝐵  ↔  ( 𝐴  +  1 )  ≤  𝐵 ) ) | 
						
							| 20 | 2 3 19 | mp2an | ⊢ ( 𝐴  <  𝐵  ↔  ( 𝐴  +  1 )  ≤  𝐵 ) | 
						
							| 21 | 7 20 | mpbi | ⊢ ( 𝐴  +  1 )  ≤  𝐵 | 
						
							| 22 | 1 | nngt0i | ⊢ 0  <  𝑇 | 
						
							| 23 |  | peano2re | ⊢ ( 𝐴  ∈  ℝ  →  ( 𝐴  +  1 )  ∈  ℝ ) | 
						
							| 24 | 11 23 | ax-mp | ⊢ ( 𝐴  +  1 )  ∈  ℝ | 
						
							| 25 | 3 | nn0rei | ⊢ 𝐵  ∈  ℝ | 
						
							| 26 | 24 25 9 | lemul2i | ⊢ ( 0  <  𝑇  →  ( ( 𝐴  +  1 )  ≤  𝐵  ↔  ( 𝑇  ·  ( 𝐴  +  1 ) )  ≤  ( 𝑇  ·  𝐵 ) ) ) | 
						
							| 27 | 22 26 | ax-mp | ⊢ ( ( 𝐴  +  1 )  ≤  𝐵  ↔  ( 𝑇  ·  ( 𝐴  +  1 ) )  ≤  ( 𝑇  ·  𝐵 ) ) | 
						
							| 28 | 21 27 | mpbi | ⊢ ( 𝑇  ·  ( 𝐴  +  1 ) )  ≤  ( 𝑇  ·  𝐵 ) | 
						
							| 29 | 9 11 | remulcli | ⊢ ( 𝑇  ·  𝐴 )  ∈  ℝ | 
						
							| 30 | 4 | nn0rei | ⊢ 𝐶  ∈  ℝ | 
						
							| 31 | 29 30 | readdcli | ⊢ ( ( 𝑇  ·  𝐴 )  +  𝐶 )  ∈  ℝ | 
						
							| 32 | 9 24 | remulcli | ⊢ ( 𝑇  ·  ( 𝐴  +  1 ) )  ∈  ℝ | 
						
							| 33 | 9 25 | remulcli | ⊢ ( 𝑇  ·  𝐵 )  ∈  ℝ | 
						
							| 34 | 31 32 33 | ltletri | ⊢ ( ( ( ( 𝑇  ·  𝐴 )  +  𝐶 )  <  ( 𝑇  ·  ( 𝐴  +  1 ) )  ∧  ( 𝑇  ·  ( 𝐴  +  1 ) )  ≤  ( 𝑇  ·  𝐵 ) )  →  ( ( 𝑇  ·  𝐴 )  +  𝐶 )  <  ( 𝑇  ·  𝐵 ) ) | 
						
							| 35 | 18 28 34 | mp2an | ⊢ ( ( 𝑇  ·  𝐴 )  +  𝐶 )  <  ( 𝑇  ·  𝐵 ) | 
						
							| 36 | 33 5 | nn0addge1i | ⊢ ( 𝑇  ·  𝐵 )  ≤  ( ( 𝑇  ·  𝐵 )  +  𝐷 ) | 
						
							| 37 | 5 | nn0rei | ⊢ 𝐷  ∈  ℝ | 
						
							| 38 | 33 37 | readdcli | ⊢ ( ( 𝑇  ·  𝐵 )  +  𝐷 )  ∈  ℝ | 
						
							| 39 | 31 33 38 | ltletri | ⊢ ( ( ( ( 𝑇  ·  𝐴 )  +  𝐶 )  <  ( 𝑇  ·  𝐵 )  ∧  ( 𝑇  ·  𝐵 )  ≤  ( ( 𝑇  ·  𝐵 )  +  𝐷 ) )  →  ( ( 𝑇  ·  𝐴 )  +  𝐶 )  <  ( ( 𝑇  ·  𝐵 )  +  𝐷 ) ) | 
						
							| 40 | 35 36 39 | mp2an | ⊢ ( ( 𝑇  ·  𝐴 )  +  𝐶 )  <  ( ( 𝑇  ·  𝐵 )  +  𝐷 ) |