Nuprl Lemma : pgeo-plsep_functionality
∀g:ProjectivePlane. ∀a,a1:Point. ∀l,l1:Line.  (a ≡ a1 
⇒ l ≡ l1 
⇒ {a ≠ l 
⇐⇒ a1 ≠ l1})
Proof
Definitions occuring in Statement : 
projective-plane: ProjectivePlane
, 
pgeo-leq: a ≡ b
, 
pgeo-peq: a ≡ b
, 
pgeo-plsep: a ≠ b
, 
pgeo-line: Line
, 
pgeo-point: Point
, 
guard: {T}
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
Definitions unfolded in proof : 
rev_implies: P 
⇐ Q
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
member: t ∈ T
, 
and: P ∧ Q
, 
iff: P 
⇐⇒ Q
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
guard: {T}
Lemmas referenced : 
pgeo-point_wf, 
pgeo-line_wf, 
pgeo-peq_wf, 
pgeo-leq_wf, 
pgeo-primitives_wf, 
projective-plane-structure_wf, 
projective-plane-structure-complete_wf, 
projective-plane_wf, 
subtype_rel_transitivity, 
projective-plane-subtype, 
projective-plane-structure-complete_subtype, 
projective-plane-structure_subtype, 
pgeo-plsep_wf, 
pgeo-peq-preserves-plsep, 
pgeo-leq-preserves-plsep, 
pgeo-leq_inversion, 
pgeo-peq-sym
Rules used in proof : 
because_Cache, 
independent_isectElimination, 
instantiate, 
hypothesis, 
applyEquality, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
independent_pairFormation, 
lambdaFormation, 
computationStep, 
sqequalTransitivity, 
sqequalReflexivity, 
sqequalRule, 
sqequalSubstitution, 
independent_functionElimination, 
dependent_functionElimination, 
rename
Latex:
\mforall{}g:ProjectivePlane.  \mforall{}a,a1:Point.  \mforall{}l,l1:Line.    (a  \mequiv{}  a1  {}\mRightarrow{}  l  \mequiv{}  l1  {}\mRightarrow{}  \{a  \mneq{}  l  \mLeftarrow{}{}\mRightarrow{}  a1  \mneq{}  l1\})
Date html generated:
2018_05_22-PM-00_45_39
Last ObjectModification:
2017_12_01-PM-05_33_39
Theory : euclidean!plane!geometry
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