Nuprl Lemma : not-parallel-implies
∀eu:EuclideanParPlane. ∀l,m,n:Line.  ((¬l || m) 
⇒ (¬(l || n ∧ m || n)))
Proof
Definitions occuring in Statement : 
euclidean-parallel-plane: EuclideanParPlane
, 
geo-Aparallel: l || m
, 
geo-line: Line
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
and: P ∧ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
false: False
, 
and: P ∧ Q
, 
member: t ∈ T
, 
guard: {T}
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
Lemmas referenced : 
geo-Aparallel_inversion, 
euclidean-planes-subtype, 
geo-Aparallel_wf, 
euclidean-plane-structure-subtype, 
subtype_rel_transitivity, 
euclidean-parallel-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
not_wf, 
geo-line_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
thin, 
sqequalHypSubstitution, 
productElimination, 
hypothesis, 
independent_functionElimination, 
introduction, 
extract_by_obid, 
dependent_functionElimination, 
hypothesisEquality, 
applyEquality, 
sqequalRule, 
voidElimination, 
productEquality, 
isectElimination, 
instantiate, 
independent_isectElimination, 
because_Cache
Latex:
\mforall{}eu:EuclideanParPlane.  \mforall{}l,m,n:Line.    ((\mneg{}l  ||  m)  {}\mRightarrow{}  (\mneg{}(l  ||  n  \mwedge{}  m  ||  n)))
Date html generated:
2018_05_22-PM-01_15_23
Last ObjectModification:
2018_04_16-AM-10_59_58
Theory : euclidean!plane!geometry
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