Nuprl Lemma : geo-parallel-right-comm
∀e:EuclideanPlane. ∀a,b,c,d:Point.  (geo-parallel(e;a;b;c;d) ⇒ geo-parallel(e;a;b;d;c))
Proof
Definitions occuring in Statement : 
geo-parallel: geo-parallel(e;a;b;c;d), 
euclidean-plane: EuclideanPlane, 
geo-point: Point, 
all: ∀x:A. B[x], 
implies: P ⇒ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
geo-parallel: geo-parallel(e;a;b;c;d), 
and: P ∧ Q, 
cand: A c∧ B, 
member: t ∈ T, 
guard: {T}, 
prop: ℙ, 
uall: ∀[x:A]. B[x], 
subtype_rel: A ⊆r B, 
uimplies: b supposing a
Lemmas referenced : 
geo-sep-sym, 
lsep-all-sym, 
geo-colinear_wf, 
geo-parallel_wf, 
geo-point_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
sqequalHypSubstitution, 
productElimination, 
thin, 
independent_pairFormation, 
cut, 
hypothesis, 
introduction, 
extract_by_obid, 
dependent_functionElimination, 
hypothesisEquality, 
independent_functionElimination, 
because_Cache, 
isectElimination, 
applyEquality, 
sqequalRule, 
instantiate, 
independent_isectElimination
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,d:Point.    (geo-parallel(e;a;b;c;d)  {}\mRightarrow{}  geo-parallel(e;a;b;d;c))
Date html generated:
2018_05_22-PM-00_13_40
Last ObjectModification:
2017_10_12-AM-11_26_49
Theory : euclidean!plane!geometry
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