| Step | Hyp | Ref | Expression | 
						
							| 1 |  | btwnexchand.1 | ⊢ ( 𝜑  →  𝑁  ∈  ℕ ) | 
						
							| 2 |  | btwnexchand.2 | ⊢ ( 𝜑  →  𝐴  ∈  ( 𝔼 ‘ 𝑁 ) ) | 
						
							| 3 |  | btwnexchand.3 | ⊢ ( 𝜑  →  𝐵  ∈  ( 𝔼 ‘ 𝑁 ) ) | 
						
							| 4 |  | btwnexchand.4 | ⊢ ( 𝜑  →  𝐶  ∈  ( 𝔼 ‘ 𝑁 ) ) | 
						
							| 5 |  | btwnexchand.5 | ⊢ ( 𝜑  →  𝐷  ∈  ( 𝔼 ‘ 𝑁 ) ) | 
						
							| 6 |  | btwnexchand.6 | ⊢ ( ( 𝜑  ∧  𝜓 )  →  𝐵  Btwn  〈 𝐴 ,  𝐶 〉 ) | 
						
							| 7 |  | btwnexchand.7 | ⊢ ( ( 𝜑  ∧  𝜓 )  →  𝐶  Btwn  〈 𝐴 ,  𝐷 〉 ) | 
						
							| 8 |  | btwnexch | ⊢ ( ( 𝑁  ∈  ℕ  ∧  ( 𝐴  ∈  ( 𝔼 ‘ 𝑁 )  ∧  𝐵  ∈  ( 𝔼 ‘ 𝑁 ) )  ∧  ( 𝐶  ∈  ( 𝔼 ‘ 𝑁 )  ∧  𝐷  ∈  ( 𝔼 ‘ 𝑁 ) ) )  →  ( ( 𝐵  Btwn  〈 𝐴 ,  𝐶 〉  ∧  𝐶  Btwn  〈 𝐴 ,  𝐷 〉 )  →  𝐵  Btwn  〈 𝐴 ,  𝐷 〉 ) ) | 
						
							| 9 | 1 2 3 4 5 8 | syl122anc | ⊢ ( 𝜑  →  ( ( 𝐵  Btwn  〈 𝐴 ,  𝐶 〉  ∧  𝐶  Btwn  〈 𝐴 ,  𝐷 〉 )  →  𝐵  Btwn  〈 𝐴 ,  𝐷 〉 ) ) | 
						
							| 10 | 9 | adantr | ⊢ ( ( 𝜑  ∧  𝜓 )  →  ( ( 𝐵  Btwn  〈 𝐴 ,  𝐶 〉  ∧  𝐶  Btwn  〈 𝐴 ,  𝐷 〉 )  →  𝐵  Btwn  〈 𝐴 ,  𝐷 〉 ) ) | 
						
							| 11 | 6 7 10 | mp2and | ⊢ ( ( 𝜑  ∧  𝜓 )  →  𝐵  Btwn  〈 𝐴 ,  𝐷 〉 ) |