Nuprl Lemma : geo-out-iff-between1
∀e:BasicGeometry. ∀p,a,b,c:Point.  (p ≠ a ⇒ p ≠ b ⇒ p ≠ c ⇒ a_p_c ⇒ (b_p_c ⇐⇒ out(p ab)))
Proof
Definitions occuring in Statement : 
geo-out: out(p ab), 
basic-geometry: BasicGeometry, 
geo-between: a_b_c, 
geo-sep: a ≠ b, 
geo-point: Point, 
all: ∀x:A. B[x], 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q
Definitions unfolded in proof : 
rev_implies: P ⇐ Q, 
uimplies: b supposing a, 
guard: {T}, 
subtype_rel: A ⊆r B, 
uall: ∀[x:A]. B[x], 
prop: ℙ, 
member: t ∈ T, 
cand: A c∧ B, 
geo-out: out(p ab), 
and: P ∧ Q, 
iff: P ⇐⇒ Q, 
implies: P ⇒ Q, 
all: ∀x:A. B[x], 
not: ¬A, 
stable: Stable{P}, 
basic-geometry: BasicGeometry, 
false: False
Lemmas referenced : 
geo-point_wf, 
geo-sep_wf, 
geo-out_wf, 
Error :basic-geo-primitives_wf, 
Error :basic-geo-structure_wf, 
basic-geometry_wf, 
subtype_rel_transitivity, 
basic-geometry-subtype, 
geo-between_wf, 
geo-sep-sym, 
geo-between-symmetry, 
geo-between-same-side2, 
not_wf, 
stable__geo-between, 
geo-between-exchange3, 
geo-between-inner-trans, 
geo-between-outer-trans
Rules used in proof : 
because_Cache, 
productElimination, 
sqequalRule, 
independent_isectElimination, 
instantiate, 
applyEquality, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
hypothesis, 
cut, 
independent_pairFormation, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
independent_functionElimination, 
dependent_functionElimination, 
rename, 
setElimination, 
voidElimination
Latex:
\mforall{}e:BasicGeometry.  \mforall{}p,a,b,c:Point.    (p  \mneq{}  a  {}\mRightarrow{}  p  \mneq{}  b  {}\mRightarrow{}  p  \mneq{}  c  {}\mRightarrow{}  a\_p\_c  {}\mRightarrow{}  (b\_p\_c  \mLeftarrow{}{}\mRightarrow{}  out(p  ab)))
Date html generated:
2017_10_02-PM-06_26_54
Last ObjectModification:
2017_08_05-PM-04_20_26
Theory : euclidean!plane!geometry
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