Nuprl Lemma : zero-angle-less-than-all
∀g:EuclideanPlane. ∀a,b,x,y,z:Point.  (a ≠ b 
⇒ x # yz 
⇒ aba < xyz)
Proof
Definitions occuring in Statement : 
geo-lt-angle: abc < xyz
, 
euclidean-plane: EuclideanPlane
, 
geo-lsep: a # bc
, 
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
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
uimplies: b supposing a
, 
prop: ℙ
, 
and: P ∧ Q
, 
geo-lt-angle: abc < xyz
, 
cand: A c∧ B
, 
iff: P 
⇐⇒ Q
, 
basic-geometry: BasicGeometry
, 
not: ¬A
, 
false: False
, 
exists: ∃x:A. B[x]
Lemmas referenced : 
geo-lsep_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-sep_wf, 
geo-point_wf, 
geo-sep-sym, 
lsep-implies-sep, 
geo-between-trivial, 
zero-angles-congruent, 
not-out-if-lsep, 
geo-out_weakening, 
geo-eq_weakening, 
geo-out-iff-colinear, 
geo-between-trivial2, 
euclidean-plane-axioms, 
geo-between_wf, 
geo-out_wf, 
istype-void, 
geo-cong-angle_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
universeIsType, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
applyEquality, 
hypothesis, 
instantiate, 
independent_isectElimination, 
sqequalRule, 
because_Cache, 
inhabitedIsType, 
dependent_functionElimination, 
independent_functionElimination, 
productElimination, 
independent_pairFormation, 
productIsType, 
functionIsType, 
dependent_pairFormation_alt
Latex:
\mforall{}g:EuclideanPlane.  \mforall{}a,b,x,y,z:Point.    (a  \mneq{}  b  {}\mRightarrow{}  x  \#  yz  {}\mRightarrow{}  aba  <  xyz)
Date html generated:
2019_10_16-PM-01_58_14
Last ObjectModification:
2019_09_27-PM-05_56_10
Theory : euclidean!plane!geometry
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