Nuprl Lemma : interior-angles-unique2-symm
∀e:EuclideanPlane. ∀a,b,c,d,a',c',p:Point.
  (c leftof ab
  
⇒ d leftof ab
  
⇒ p leftof ab
  
⇒ out(b aa')
  
⇒ out(b cc')
  
⇒ a'_p_c'
  
⇒ p ≠ c'
  
⇒ abd < abc
  
⇒ abp ≅a abd
  
⇒ out(b dp))
Proof
Definitions occuring in Statement : 
geo-lt-angle: abc < xyz
, 
geo-out: out(p ab)
, 
geo-cong-angle: abc ≅a xyz
, 
euclidean-plane: EuclideanPlane
, 
geo-left: a leftof bc
, 
geo-between: a_b_c
, 
geo-sep: a ≠ b
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
geo-cong-angle: abc ≅a xyz
, 
and: P ∧ Q
, 
member: t ∈ T
, 
guard: {T}
, 
exists: ∃x:A. B[x]
, 
basic-geometry: BasicGeometry
, 
euclidean-plane: EuclideanPlane
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
basic-geometry-: BasicGeometry-
, 
uiff: uiff(P;Q)
, 
cand: A c∧ B
, 
geo-tri: Triangle(a;b;c)
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
left-implies-sep, 
geo-proper-extend-exists, 
geo-O_wf, 
geo-X_wf, 
geo-sep-O-X, 
geo-cong-angle_wf, 
geo-lt-angle_wf, 
geo-sep_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-between_wf, 
geo-out_wf, 
geo-left_wf, 
geo-point_wf, 
geo-sep-sym, 
geo-strict-between-sep3, 
geo-left-out-3, 
geo-out-if-between, 
geo-strict-between-sym, 
Euclid-Prop7, 
geo-congruent-iff-length, 
geo-cong-angle-refl, 
geo-out_weakening, 
geo-eq_weakening, 
euclidean-plane-axioms, 
geo-cong-angle-symm2, 
geo-congruent-refl, 
out-preserves-angle-cong_1, 
geo-cong-angle-transitivity, 
geo-sas, 
geo-out-iff-between1, 
geo-between-symmetry, 
geo-strict-between-implies-between, 
geo-out_functionality
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
sqequalHypSubstitution, 
productElimination, 
thin, 
introduction, 
extract_by_obid, 
dependent_functionElimination, 
hypothesisEquality, 
independent_functionElimination, 
hypothesis, 
sqequalRule, 
setElimination, 
rename, 
because_Cache, 
universeIsType, 
isectElimination, 
applyEquality, 
instantiate, 
independent_isectElimination, 
inhabitedIsType, 
dependent_set_memberEquality_alt, 
equalitySymmetry, 
independent_pairFormation
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,d,a',c',p:Point.
    (c  leftof  ab
    {}\mRightarrow{}  d  leftof  ab
    {}\mRightarrow{}  p  leftof  ab
    {}\mRightarrow{}  out(b  aa')
    {}\mRightarrow{}  out(b  cc')
    {}\mRightarrow{}  a'\_p\_c'
    {}\mRightarrow{}  p  \mneq{}  c'
    {}\mRightarrow{}  abd  <  abc
    {}\mRightarrow{}  abp  \mcong{}\msuba{}  abd
    {}\mRightarrow{}  out(b  dp))
Date html generated:
2019_10_16-PM-02_17_35
Last ObjectModification:
2019_08_12-PM-09_00_01
Theory : euclidean!plane!geometry
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