Nuprl Lemma : Euclid-drop-perp-1

e:EuclideanPlane. ∀a:Point. ∀b:{b:Point| a ≠ b} . ∀c:{c:Point| ∀x:Point. (Colinear(a;b;x)  c ≠ x)} .
  ∃p:Point. (Colinear(a;b;p) ∧ ab  ⊥pc)


Proof




Definitions occuring in Statement :  geo-perp-in: ab  ⊥cd euclidean-plane: EuclideanPlane geo-colinear: Colinear(a;b;c) geo-sep: a ≠ b geo-point: Point all: x:A. B[x] exists: x:A. B[x] implies:  Q and: P ∧ Q set: {x:A| B[x]} 
Definitions unfolded in proof :  all: x:A. B[x] member: t ∈ T exists: x:A. B[x] sq_exists: x:A [B[x]] and: P ∧ Q cand: c∧ B subtype_rel: A ⊆B uall: [x:A]. B[x] guard: {T} uimplies: supposing a sq_stable: SqStable(P) implies:  Q iff: ⇐⇒ Q rev_implies:  Q geo-perp-in: ab  ⊥cd squash: T basic-geometry: BasicGeometry geo-colinear-set: geo-colinear-set(e; L) l_all: (∀x∈L.P[x]) top: Top int_seg: {i..j-} lelt: i ≤ j < k le: A ≤ B less_than': less_than'(a;b) false: False not: ¬A prop: less_than: a < b true: True select: L[n] cons: [a b] subtract: m so_lambda: λ2x.t[x] so_apply: x[s]
Lemmas referenced :  Euclid-drop-perp-0 sq_stable__colinear euclidean-plane-structure-subtype euclidean-plane-subtype subtype_rel_transitivity euclidean-plane_wf euclidean-plane-structure_wf geo-primitives_wf euclidean-plane-axioms sq_stable__from_stable geo-perp-in_wf stable__geo-perp-in geo-perp-in-iff2 geo-colinear-is-colinear-set length_of_cons_lemma length_of_nil_lemma false_wf lelt_wf geo-colinear_wf geo-point_wf all_wf geo-sep_wf
Rules used in proof :  cut introduction extract_by_obid sqequalSubstitution sqequalTransitivity computationStep sqequalReflexivity lambdaFormation hypothesis sqequalHypSubstitution dependent_functionElimination thin hypothesisEquality setElimination rename productElimination dependent_pairFormation applyEquality instantiate isectElimination independent_isectElimination sqequalRule independent_functionElimination imageMemberEquality baseClosed imageElimination independent_pairFormation because_Cache isect_memberEquality voidElimination voidEquality dependent_set_memberEquality natural_numberEquality productEquality setEquality lambdaEquality functionEquality

Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a:Point.  \mforall{}b:\{b:Point|  a  \mneq{}  b\}  .
\mforall{}c:\{c:Point|  \mforall{}x:Point.  (Colinear(a;b;x)  {}\mRightarrow{}  c  \mneq{}  x)\}  .
    \mexists{}p:Point.  (Colinear(a;b;p)  \mwedge{}  ab    \mbot{}p  pc)



Date html generated: 2018_05_22-PM-00_11_58
Last ObjectModification: 2018_05_11-PM-03_22_52

Theory : euclidean!plane!geometry


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