Theorem mapdpg

Description: Part 1 of proof of the first fundamental theorem of projective geometry. Part (1) in Baer p. 44. Our notation corresponds to Baer's as follows: M for *, N{ } for F(), J{ } for G(), X for x, G for x', Y for y, h for y'. TODO: Rename variables per mapdhval . (Contributed by NM, 22-Mar-2015)

	Ref	Expression
Hypotheses	mapdpg.h	⊢ 𝐻 = ( LHyp ‘ 𝐾 )
	mapdpg.m	⊢ 𝑀 = ( ( mapd ‘ 𝐾 ) ‘ 𝑊 )
	mapdpg.u	⊢ 𝑈 = ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 )
	mapdpg.v	⊢ 𝑉 = ( Base ‘ 𝑈 )
	mapdpg.s	⊢ − = ( -g ‘ 𝑈 )
	mapdpg.z	⊢ 0 = ( 0g ‘ 𝑈 )
	mapdpg.n	⊢ 𝑁 = ( LSpan ‘ 𝑈 )
	mapdpg.c	⊢ 𝐶 = ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 )
	mapdpg.f	⊢ 𝐹 = ( Base ‘ 𝐶 )
	mapdpg.r	⊢ 𝑅 = ( -g ‘ 𝐶 )
	mapdpg.j	⊢ 𝐽 = ( LSpan ‘ 𝐶 )
	mapdpg.k	⊢ ( 𝜑 → ( 𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻 ) )
	mapdpg.x	⊢ ( 𝜑 → 𝑋 ∈ ( 𝑉 ∖ { 0 } ) )
	mapdpg.y	⊢ ( 𝜑 → 𝑌 ∈ ( 𝑉 ∖ { 0 } ) )
	mapdpg.g	⊢ ( 𝜑 → 𝐺 ∈ 𝐹 )
	mapdpg.ne	⊢ ( 𝜑 → ( 𝑁 ‘ { 𝑋 } ) ≠ ( 𝑁 ‘ { 𝑌 } ) )
	mapdpg.e	⊢ ( 𝜑 → ( 𝑀 ‘ ( 𝑁 ‘ { 𝑋 } ) ) = ( 𝐽 ‘ { 𝐺 } ) )
Assertion	mapdpg	⊢ ( 𝜑 → ∃! ℎ ∈ 𝐹 ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) )

Proof

Step	Hyp	Ref	Expression
1		mapdpg.h	⊢ 𝐻 = ( LHyp ‘ 𝐾 )
2		mapdpg.m	⊢ 𝑀 = ( ( mapd ‘ 𝐾 ) ‘ 𝑊 )
3		mapdpg.u	⊢ 𝑈 = ( ( DVecH ‘ 𝐾 ) ‘ 𝑊 )
4		mapdpg.v	⊢ 𝑉 = ( Base ‘ 𝑈 )
5		mapdpg.s	⊢ − = ( -g ‘ 𝑈 )
6		mapdpg.z	⊢ 0 = ( 0g ‘ 𝑈 )
7		mapdpg.n	⊢ 𝑁 = ( LSpan ‘ 𝑈 )
8		mapdpg.c	⊢ 𝐶 = ( ( LCDual ‘ 𝐾 ) ‘ 𝑊 )
9		mapdpg.f	⊢ 𝐹 = ( Base ‘ 𝐶 )
10		mapdpg.r	⊢ 𝑅 = ( -g ‘ 𝐶 )
11		mapdpg.j	⊢ 𝐽 = ( LSpan ‘ 𝐶 )
12		mapdpg.k	⊢ ( 𝜑 → ( 𝐾 ∈ HL ∧ 𝑊 ∈ 𝐻 ) )
13		mapdpg.x	⊢ ( 𝜑 → 𝑋 ∈ ( 𝑉 ∖ { 0 } ) )
14		mapdpg.y	⊢ ( 𝜑 → 𝑌 ∈ ( 𝑉 ∖ { 0 } ) )
15		mapdpg.g	⊢ ( 𝜑 → 𝐺 ∈ 𝐹 )
16		mapdpg.ne	⊢ ( 𝜑 → ( 𝑁 ‘ { 𝑋 } ) ≠ ( 𝑁 ‘ { 𝑌 } ) )
17		mapdpg.e	⊢ ( 𝜑 → ( 𝑀 ‘ ( 𝑁 ‘ { 𝑋 } ) ) = ( 𝐽 ‘ { 𝐺 } ) )
18	1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17	mapdpglem24	⊢ ( 𝜑 → ∃ ℎ ∈ 𝐹 ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) )
19	1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17	mapdpglem32	⊢ ( ( 𝜑 ∧ ( ℎ ∈ 𝐹 ∧ 𝑖 ∈ 𝐹 ) ∧ ( ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) ∧ ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { 𝑖 } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 𝑖 ) } ) ) ) ) → ℎ = 𝑖 )
20	19	3exp	⊢ ( 𝜑 → ( ( ℎ ∈ 𝐹 ∧ 𝑖 ∈ 𝐹 ) → ( ( ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) ∧ ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { 𝑖 } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 𝑖 ) } ) ) ) → ℎ = 𝑖 ) ) )
21	20	ralrimivv	⊢ ( 𝜑 → ∀ ℎ ∈ 𝐹 ∀ 𝑖 ∈ 𝐹 ( ( ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) ∧ ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { 𝑖 } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 𝑖 ) } ) ) ) → ℎ = 𝑖 ) )
22		sneq	⊢ ( ℎ = 𝑖 → { ℎ } = { 𝑖 } )
23	22	fveq2d	⊢ ( ℎ = 𝑖 → ( 𝐽 ‘ { ℎ } ) = ( 𝐽 ‘ { 𝑖 } ) )
24	23	eqeq2d	⊢ ( ℎ = 𝑖 → ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ↔ ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { 𝑖 } ) ) )
25		oveq2	⊢ ( ℎ = 𝑖 → ( 𝐺 𝑅 ℎ ) = ( 𝐺 𝑅 𝑖 ) )
26	25	sneqd	⊢ ( ℎ = 𝑖 → { ( 𝐺 𝑅 ℎ ) } = { ( 𝐺 𝑅 𝑖 ) } )
27	26	fveq2d	⊢ ( ℎ = 𝑖 → ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) = ( 𝐽 ‘ { ( 𝐺 𝑅 𝑖 ) } ) )
28	27	eqeq2d	⊢ ( ℎ = 𝑖 → ( ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ↔ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 𝑖 ) } ) ) )
29	24 28	anbi12d	⊢ ( ℎ = 𝑖 → ( ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) ↔ ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { 𝑖 } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 𝑖 ) } ) ) ) )
30	29	reu4	⊢ ( ∃! ℎ ∈ 𝐹 ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) ↔ ( ∃ ℎ ∈ 𝐹 ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) ∧ ∀ ℎ ∈ 𝐹 ∀ 𝑖 ∈ 𝐹 ( ( ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) ∧ ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { 𝑖 } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 𝑖 ) } ) ) ) → ℎ = 𝑖 ) ) )
31	18 21 30	sylanbrc	⊢ ( 𝜑 → ∃! ℎ ∈ 𝐹 ( ( 𝑀 ‘ ( 𝑁 ‘ { 𝑌 } ) ) = ( 𝐽 ‘ { ℎ } ) ∧ ( 𝑀 ‘ ( 𝑁 ‘ { ( 𝑋 − 𝑌 ) } ) ) = ( 𝐽 ‘ { ( 𝐺 𝑅 ℎ ) } ) ) )