Nuprl Lemma : geo-intersect-symmetry
∀e:EuclideanPlane. ∀l,m:LINE.  (l \/ m ⇒ m \/ l)
Proof
Definitions occuring in Statement : 
geo-intersect: L \/ M, 
geoline: LINE, 
euclidean-plane: EuclideanPlane, 
all: ∀x:A. B[x], 
implies: P ⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
exists: ∃x:A. B[x], 
rev_implies: P ⇐ Q, 
prop: ℙ, 
uall: ∀[x:A]. B[x], 
subtype_rel: A ⊆r B, 
guard: {T}, 
uimplies: b supposing a, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
geo-strict-between: a-b-c, 
cand: A c∧ B
Lemmas referenced : 
geo-intersect-iff2, 
geo-strict-between_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-incident_wf, 
geo-left_wf, 
exists_wf, 
geo-point_wf, 
geo-intersect_wf, 
geoline_wf, 
geo-between-symmetry, 
geo-sep-sym
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
productElimination, 
independent_functionElimination, 
dependent_pairFormation, 
independent_pairFormation, 
productEquality, 
isectElimination, 
applyEquality, 
instantiate, 
independent_isectElimination, 
sqequalRule, 
because_Cache, 
lambdaEquality
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}l,m:LINE.    (l  \mbackslash{}/  m  {}\mRightarrow{}  m  \mbackslash{}/  l)
Date html generated:
2018_05_22-PM-01_06_34
Last ObjectModification:
2018_05_10-PM-06_10_09
Theory : euclidean!plane!geometry
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