Nuprl Lemma : use-SC
∀e:EuclideanPlane. ∀a,b,c,d:Point.
  (a ≠ b 
⇒ c_b_d 
⇒ (∃u,v:Point. (cu ≅ cd ∧ cv ≅ cd ∧ a_b_u ∧ (v_b_u ∧ Colinear(a;b;v)) ∧ (b ≠ d 
⇒ v ≠ u))))
Proof
Definitions occuring in Statement : 
euclidean-plane: EuclideanPlane
, 
geo-colinear: Colinear(a;b;c)
, 
geo-congruent: ab ≅ cd
, 
geo-between: a_b_c
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
exists: ∃x:A. B[x]
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
exists: ∃x:A. B[x]
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
euclidean-plane: EuclideanPlane
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
guard: {T}
, 
uimplies: b supposing a
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
geo-colinear: Colinear(a;b;c)
, 
not: ¬A
, 
false: False
Lemmas referenced : 
geo-SCO_wf, 
geo-sep-sym, 
geo-sep_wf, 
geo-between_wf, 
geo-SCS_wf, 
geo-point_wf, 
geo-congruent_wf, 
geo-colinear_wf, 
set_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
equal_wf, 
exists_wf, 
not_wf, 
squash_wf, 
sq_stable__geo-congruent, 
geo-between-symmetry, 
sq_stable__geo-between, 
sq_stable__and, 
sq_stable__colinear, 
sq_stable__all, 
sq_stable__geo-sep
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
dependent_pairFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
setElimination, 
rename, 
because_Cache, 
hypothesis, 
dependent_functionElimination, 
hypothesisEquality, 
independent_functionElimination, 
independent_pairFormation, 
dependent_set_memberEquality, 
productEquality, 
applyEquality, 
sqequalRule, 
lambdaEquality, 
setEquality, 
functionEquality, 
productElimination, 
instantiate, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
isect_memberEquality, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
voidElimination
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,d:Point.
    (a  \mneq{}  b
    {}\mRightarrow{}  c\_b\_d
    {}\mRightarrow{}  (\mexists{}u,v:Point.  (cu  \00D0  cd  \mwedge{}  cv  \00D0  cd  \mwedge{}  a\_b\_u  \mwedge{}  (v\_b\_u  \mwedge{}  Colinear(a;b;v))  \mwedge{}  (b  \mneq{}  d  {}\mRightarrow{}  v  \mneq{}  u))))
Date html generated:
2017_10_02-PM-04_40_51
Last ObjectModification:
2017_08_12-PM-08_36_40
Theory : euclidean!plane!geometry
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