Theorem hilbert1.2 32774

Description: There is at most one line through any two distinct points. Hilbert's axiom I.2 for geometry. (Contributed by Scott Fenton, 29-Oct-2013.) (Revised by NM, 17-Jun-2017.)

Assertion

Ref	Expression
hilbert1.2	⊢ (𝑃 ≠ 𝑄 → ∃*𝑥 ∈ LinesEE (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥))

Distinct variable groups:   𝑥,𝑃   𝑥,𝑄

Proof of Theorem hilbert1.2

Dummy variable 𝑦 is distinct from all other variables.

Step	Hyp	Ref	Expression
1		an4 647	. . . . 5 ⊢ (((𝑥 ∈ LinesEE ∧ 𝑦 ∈ LinesEE) ∧ ((𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥) ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))) ↔ ((𝑥 ∈ LinesEE ∧ (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥)) ∧ (𝑦 ∈ LinesEE ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))))
2		simprl 788	. . . . . . . . 9 ⊢ ((𝑃 ≠ 𝑄 ∧ (𝑥 ∈ LinesEE ∧ (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥))) → 𝑥 ∈ LinesEE)
3		simprr 790	. . . . . . . . 9 ⊢ ((𝑃 ≠ 𝑄 ∧ (𝑥 ∈ LinesEE ∧ (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥))) → (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥))
4		simpl 475	. . . . . . . . 9 ⊢ ((𝑃 ≠ 𝑄 ∧ (𝑥 ∈ LinesEE ∧ (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥))) → 𝑃 ≠ 𝑄)
5		linethru 32772	. . . . . . . . 9 ⊢ ((𝑥 ∈ LinesEE ∧ (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥) ∧ 𝑃 ≠ 𝑄) → 𝑥 = (𝑃Line𝑄))
6	2, 3, 4, 5	syl3anc 1491	. . . . . . . 8 ⊢ ((𝑃 ≠ 𝑄 ∧ (𝑥 ∈ LinesEE ∧ (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥))) → 𝑥 = (𝑃Line𝑄))
7	6	ex 402	. . . . . . 7 ⊢ (𝑃 ≠ 𝑄 → ((𝑥 ∈ LinesEE ∧ (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥)) → 𝑥 = (𝑃Line𝑄)))
8		simprl 788	. . . . . . . . 9 ⊢ ((𝑃 ≠ 𝑄 ∧ (𝑦 ∈ LinesEE ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))) → 𝑦 ∈ LinesEE)
9		simprr 790	. . . . . . . . 9 ⊢ ((𝑃 ≠ 𝑄 ∧ (𝑦 ∈ LinesEE ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))) → (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))
10		simpl 475	. . . . . . . . 9 ⊢ ((𝑃 ≠ 𝑄 ∧ (𝑦 ∈ LinesEE ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))) → 𝑃 ≠ 𝑄)
11		linethru 32772	. . . . . . . . 9 ⊢ ((𝑦 ∈ LinesEE ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦) ∧ 𝑃 ≠ 𝑄) → 𝑦 = (𝑃Line𝑄))
12	8, 9, 10, 11	syl3anc 1491	. . . . . . . 8 ⊢ ((𝑃 ≠ 𝑄 ∧ (𝑦 ∈ LinesEE ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))) → 𝑦 = (𝑃Line𝑄))
13	12	ex 402	. . . . . . 7 ⊢ (𝑃 ≠ 𝑄 → ((𝑦 ∈ LinesEE ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦)) → 𝑦 = (𝑃Line𝑄)))
14	7, 13	anim12d 603	. . . . . 6 ⊢ (𝑃 ≠ 𝑄 → (((𝑥 ∈ LinesEE ∧ (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥)) ∧ (𝑦 ∈ LinesEE ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))) → (𝑥 = (𝑃Line𝑄) ∧ 𝑦 = (𝑃Line𝑄))))
15		eqtr3 2821	. . . . . 6 ⊢ ((𝑥 = (𝑃Line𝑄) ∧ 𝑦 = (𝑃Line𝑄)) → 𝑥 = 𝑦)
16	14, 15	syl6 35	. . . . 5 ⊢ (𝑃 ≠ 𝑄 → (((𝑥 ∈ LinesEE ∧ (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥)) ∧ (𝑦 ∈ LinesEE ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))) → 𝑥 = 𝑦))
17	1, 16	syl5bi 234	. . . 4 ⊢ (𝑃 ≠ 𝑄 → (((𝑥 ∈ LinesEE ∧ 𝑦 ∈ LinesEE) ∧ ((𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥) ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦))) → 𝑥 = 𝑦))
18	17	expd 405	. . 3 ⊢ (𝑃 ≠ 𝑄 → ((𝑥 ∈ LinesEE ∧ 𝑦 ∈ LinesEE) → (((𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥) ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦)) → 𝑥 = 𝑦)))
19	18	ralrimivv 3152	. 2 ⊢ (𝑃 ≠ 𝑄 → ∀𝑥 ∈ LinesEE ∀𝑦 ∈ LinesEE (((𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥) ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦)) → 𝑥 = 𝑦))
20		eleq2w 2863	. . . 4 ⊢ (𝑥 = 𝑦 → (𝑃 ∈ 𝑥 ↔ 𝑃 ∈ 𝑦))
21		eleq2w 2863	. . . 4 ⊢ (𝑥 = 𝑦 → (𝑄 ∈ 𝑥 ↔ 𝑄 ∈ 𝑦))
22	20, 21	anbi12d 625	. . 3 ⊢ (𝑥 = 𝑦 → ((𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥) ↔ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦)))
23	22	rmo4 3596	. 2 ⊢ (∃*𝑥 ∈ LinesEE (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥) ↔ ∀𝑥 ∈ LinesEE ∀𝑦 ∈ LinesEE (((𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥) ∧ (𝑃 ∈ 𝑦 ∧ 𝑄 ∈ 𝑦)) → 𝑥 = 𝑦))
24	19, 23	sylibr 226	1 ⊢ (𝑃 ≠ 𝑄 → ∃*𝑥 ∈ LinesEE (𝑃 ∈ 𝑥 ∧ 𝑄 ∈ 𝑥))

Syntax hints:   → wi 4   ∧ wa 385   = wceq 1653   ∈ wcel 2157   ≠ wne 2972  ∀wral 3090  ∃*wrmo 3093  (class class class)co 6879  Linecline2 32753  LinesEEclines2 32755

This theorem was proved from axioms:  ax-mp 5  ax-1 6  ax-2 7  ax-3 8  ax-gen 1891  ax-4 1905  ax-5 2006  ax-6 2072  ax-7 2107  ax-8 2159  ax-9 2166  ax-10 2185  ax-11 2200  ax-12 2213  ax-13 2378  ax-ext 2778  ax-rep 4965  ax-sep 4976  ax-nul 4984  ax-pow 5036  ax-pr 5098  ax-un 7184  ax-inf2 8789  ax-cnex 10281  ax-resscn 10282  ax-1cn 10283  ax-icn 10284  ax-addcl 10285  ax-addrcl 10286  ax-mulcl 10287  ax-mulrcl 10288  ax-mulcom 10289  ax-addass 10290  ax-mulass 10291  ax-distr 10292  ax-i2m1 10293  ax-1ne0 10294  ax-1rid 10295  ax-rnegex 10296  ax-rrecex 10297  ax-cnre 10298  ax-pre-lttri 10299  ax-pre-lttrn 10300  ax-pre-ltadd 10301  ax-pre-mulgt0 10302  ax-pre-sup 10303

This theorem depends on definitions:  df-bi 199  df-an 386  df-or 875  df-3or 1109  df-3an 1110  df-tru 1657  df-fal 1667  df-ex 1876  df-nf 1880  df-sb 2065  df-mo 2592  df-eu 2610  df-clab 2787  df-cleq 2793  df-clel 2796  df-nfc 2931  df-ne 2973  df-nel 3076  df-ral 3095  df-rex 3096  df-reu 3097  df-rmo 3098  df-rab 3099  df-v 3388  df-sbc 3635  df-csb 3730  df-dif 3773  df-un 3775  df-in 3777  df-ss 3784  df-pss 3786  df-nul 4117  df-if 4279  df-pw 4352  df-sn 4370  df-pr 4372  df-tp 4374  df-op 4376  df-uni 4630  df-int 4669  df-iun 4713  df-br 4845  df-opab 4907  df-mpt 4924  df-tr 4947  df-id 5221  df-eprel 5226  df-po 5234  df-so 5235  df-fr 5272  df-se 5273  df-we 5274  df-xp 5319  df-rel 5320  df-cnv 5321  df-co 5322  df-dm 5323  df-rn 5324  df-res 5325  df-ima 5326  df-pred 5899  df-ord 5945  df-on 5946  df-lim 5947  df-suc 5948  df-iota 6065  df-fun 6104  df-fn 6105  df-f 6106  df-f1 6107  df-fo 6108  df-f1o 6109  df-fv 6110  df-isom 6111  df-riota 6840  df-ov 6882  df-oprab 6883  df-mpt2 6884  df-om 7301  df-1st 7402  df-2nd 7403  df-wrecs 7646  df-recs 7708  df-rdg 7746  df-1o 7800  df-oadd 7804  df-er 7983  df-ec 7985  df-map 8098  df-en 8197  df-dom 8198  df-sdom 8199  df-fin 8200  df-sup 8591  df-oi 8658  df-card 9052  df-pnf 10366  df-mnf 10367  df-xr 10368  df-ltxr 10369  df-le 10370  df-sub 10559  df-neg 10560  df-div 10978  df-nn 11314  df-2 11375  df-3 11376  df-n0 11580  df-z 11666  df-uz 11930  df-rp 12074  df-ico 12429  df-icc 12430  df-fz 12580  df-fzo 12720  df-seq 13055  df-exp 13114  df-hash 13370  df-cj 14179  df-re 14180  df-im 14181  df-sqrt 14315  df-abs 14316  df-clim 14559  df-sum 14757  df-ee 26127  df-btwn 26128  df-cgr 26129  df-ofs 32602  df-colinear 32658  df-ifs 32659  df-cgr3 32660  df-fs 32661  df-line2 32756  df-lines2 32758

This theorem is referenced by:  linethrueu  32775