Nuprl Lemma : unique-angles-in-half-plane-better2
∀e:EuclideanPlane. ∀a,b,c,q:Point.  (a leftof bc ⇒ q leftof bc ⇒ qcb ≅a acb ⇒ out(c aq))
Proof
Definitions occuring in Statement : 
geo-out: out(p ab), 
geo-cong-angle: abc ≅a xyz, 
euclidean-plane: EuclideanPlane, 
geo-left: a leftof bc, 
geo-point: Point, 
all: ∀x:A. B[x], 
implies: P ⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
basic-geometry: BasicGeometry, 
euclidean-plane: EuclideanPlane, 
guard: {T}, 
and: P ∧ Q, 
exists: ∃x:A. B[x], 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
subtype_rel: A ⊆r B, 
uimplies: b supposing a, 
uiff: uiff(P;Q), 
oriented-plane: OrientedPlane, 
basic-geometry-: BasicGeometry-, 
cand: A c∧ B, 
iff: P ⇐⇒ Q
Lemmas referenced : 
geo-proper-extend-exists, 
geo-O_wf, 
geo-X_wf, 
left-implies-sep, 
geo-sep-O-X, 
geo-cong-angle_wf, 
geo-left_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-point_wf, 
geo-sep-sym, 
geo-strict-between-sep3, 
Euclid-Prop7, 
geo-congruent-iff-length, 
left-between-implies-right1, 
geo-strict-between-implies-between, 
left-between-implies-right2, 
geo-congruent-refl, 
geo-sas2, 
geo-cong-angle-symmetry, 
geo-cong-angle-transitivity, 
geo-cong-angle-refl, 
geo-out_weakening, 
geo-eq_weakening, 
out-preserves-angle-cong_1, 
geo-out-if-between, 
geo-strict-between-sym, 
geo-eq_inversion, 
geo-out_functionality
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
sqequalRule, 
hypothesisEquality, 
setElimination, 
rename, 
hypothesis, 
because_Cache, 
independent_functionElimination, 
productElimination, 
universeIsType, 
isectElimination, 
applyEquality, 
instantiate, 
independent_isectElimination, 
inhabitedIsType, 
dependent_set_memberEquality_alt, 
equalitySymmetry, 
independent_pairFormation
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,q:Point.    (a  leftof  bc  {}\mRightarrow{}  q  leftof  bc  {}\mRightarrow{}  qcb  \mcong{}\msuba{}  acb  {}\mRightarrow{}  out(c  aq))
Date html generated:
2019_10_16-PM-01_54_07
Last ObjectModification:
2019_08_12-PM-02_29_37
Theory : euclidean!plane!geometry
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