Nuprl Lemma : pgeo-lsep-or
∀g:BasicProjectivePlane. ∀l,m,n:Line.  (l ≠ m 
⇒ (l ≠ n ∨ n ≠ m))
Proof
Definitions occuring in Statement : 
basic-projective-plane: BasicProjectivePlane
, 
pgeo-lsep: l ≠ m
, 
pgeo-line: Line
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
Definitions unfolded in proof : 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
guard: {T}
, 
or: P ∨ Q
, 
basic-projective-plane: BasicProjectivePlane
, 
member: t ∈ T
, 
and: P ∧ Q
, 
exists: ∃x:A. B[x]
, 
pgeo-lsep: l ≠ m
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
Lemmas referenced : 
pgeo-line_wf, 
pgeo-primitives_wf, 
projective-plane-structure_wf, 
basic-projective-plane_wf, 
subtype_rel_transitivity, 
basic-projective-plane-subtype, 
projective-plane-structure_subtype, 
pgeo-lsep_wf, 
PL-sep-or, 
pgeo-plsep-to-lsep
Rules used in proof : 
independent_isectElimination, 
instantiate, 
because_Cache, 
applyEquality, 
isectElimination, 
inrFormation, 
sqequalRule, 
unionElimination, 
independent_functionElimination, 
hypothesisEquality, 
rename, 
setElimination, 
dependent_functionElimination, 
extract_by_obid, 
introduction, 
thin, 
productElimination, 
sqequalHypSubstitution, 
hypothesis, 
cut, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
inlFormation
Latex:
\mforall{}g:BasicProjectivePlane.  \mforall{}l,m,n:Line.    (l  \mneq{}  m  {}\mRightarrow{}  (l  \mneq{}  n  \mvee{}  n  \mneq{}  m))
Date html generated:
2018_05_22-PM-00_43_16
Last ObjectModification:
2017_11_30-AM-06_49_34
Theory : euclidean!plane!geometry
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