Nuprl Lemma : geo-line-eq-preserves-incidence
∀g:EuclideanPlane. ∀a:Point. ∀l,m:Line.  (a I l 
⇒ l ≡ m 
⇒ a I m)
Proof
Definitions occuring in Statement : 
geo-incident: p I L
, 
geo-line-eq: l ≡ m
, 
geo-line: Line
, 
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
, 
geoline: LINE
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
so_lambda: λ2x y.t[x; y]
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s1;s2]
, 
uimplies: b supposing a
, 
squash: ↓T
, 
prop: ℙ
, 
true: True
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
Lemmas referenced : 
quotient-member-eq, 
geo-line-eq_wf, 
geo-line_wf, 
geo-line-eq-equiv, 
geo-incident_wf, 
squash_wf, 
true_wf, 
geoline_wf, 
subtype_rel_self, 
iff_weakening_equal, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geoline-subtype1, 
geo-point_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
sqequalRule, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
because_Cache, 
lambdaEquality, 
hypothesisEquality, 
applyEquality, 
hypothesis, 
dependent_functionElimination, 
independent_isectElimination, 
independent_functionElimination, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
instantiate, 
universeEquality, 
productElimination
Latex:
\mforall{}g:EuclideanPlane.  \mforall{}a:Point.  \mforall{}l,m:Line.    (a  I  l  {}\mRightarrow{}  l  \mequiv{}  m  {}\mRightarrow{}  a  I  m)
Date html generated:
2018_05_22-PM-01_04_28
Last ObjectModification:
2018_05_11-PM-06_49_43
Theory : euclidean!plane!geometry
Home
Index