Nuprl Lemma : lt-angle-irrefl
∀e:EuclideanPlane. ∀a,b,c,x,y,z:Point.  (abc < xyz 
⇒ (¬xyz < abc))
Proof
Definitions occuring in Statement : 
geo-lt-angle: abc < xyz
, 
euclidean-plane: EuclideanPlane
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
false: False
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
uimplies: b supposing a
, 
or: P ∨ Q
, 
stable: Stable{P}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
basic-geometry-: BasicGeometry-
, 
geo-lt-angle: abc < xyz
, 
exists: ∃x:A. B[x]
, 
geo-cong-angle: abc ≅a xyz
, 
geo-eq: a ≡ b
, 
oriented-plane: OrientedPlane
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
geo-lt-angle_wf, 
geo-point_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
stable__false, 
false_wf, 
geo-lsep_wf, 
not_wf, 
istype-void, 
minimal-double-negation-hyp-elim, 
not-lsep-iff-colinear, 
minimal-not-not-excluded-middle, 
lt-angle-not-cong, 
geo-lt-angle-trans, 
geo-colinear-cases, 
geo-eq_wf, 
geo-strict-between_wf, 
not-lt-zero-angle, 
geo-between_wf, 
geo-between-trivial, 
geo-colinear_functionality, 
geo-eq_weakening, 
geo-lsep_functionality, 
geo-lt-angle_functionality, 
geo-between_functionality, 
straight-angles-not-lt2, 
geo-strict-between-implies-between, 
geo-between-symmetry, 
zero-angles-congruent, 
geo-sep-sym, 
lt-angle-not-cong2, 
straight-angles-not-lt
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
thin, 
because_Cache, 
hypothesis, 
sqequalHypSubstitution, 
independent_functionElimination, 
voidElimination, 
universeIsType, 
introduction, 
extract_by_obid, 
dependent_functionElimination, 
hypothesisEquality, 
inhabitedIsType, 
isectElimination, 
applyEquality, 
instantiate, 
independent_isectElimination, 
sqequalRule, 
unionEquality, 
functionEquality, 
unionIsType, 
functionIsType, 
unionElimination, 
productElimination, 
inlFormation_alt, 
inrFormation_alt
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,x,y,z:Point.    (abc  <  xyz  {}\mRightarrow{}  (\mneg{}xyz  <  abc))
Date html generated:
2019_10_16-PM-02_02_27
Last ObjectModification:
2019_09_12-AM-11_41_08
Theory : euclidean!plane!geometry
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