Nuprl Lemma : congruence-preserves-between_symmetric-points2
∀e:BasicGeometry. ∀a,b,c,b',c':Point.
  (a_b_c 
⇒ Colinear(a;c;c') 
⇒ ab ≅ ab' 
⇒ ac ≅ ac' 
⇒ b'-a-b 
⇒ (a_b'_c' ∨ a_b_c'))
Proof
Definitions occuring in Statement : 
basic-geometry: BasicGeometry
, 
geo-colinear: Colinear(a;b;c)
, 
geo-strict-between: a-b-c
, 
geo-congruent: ab ≅ cd
, 
geo-between: a_b_c
, 
geo-point: Point
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
or: P ∨ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
guard: {T}
, 
uimplies: b supposing a
, 
exists: ∃x:A. B[x]
, 
prop: ℙ
, 
and: P ∧ Q
, 
uiff: uiff(P;Q)
, 
basic-geometry: BasicGeometry
, 
euclidean-plane: EuclideanPlane
, 
basic-geometry-: BasicGeometry-
, 
or: P ∨ Q
, 
not: ¬A
, 
false: False
, 
geo-eq: a ≡ b
, 
iff: P 
⇐⇒ Q
, 
geo-strict-between: a-b-c
, 
squash: ↓T
, 
true: True
Lemmas referenced : 
geo-extend-exists, 
geo-sep-sym, 
geo-strict-between-sep2, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
basic-geometry-subtype, 
subtype_rel_transitivity, 
geo-strict-between_wf, 
basic-geometry_wf, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-congruent_wf, 
geo-colinear_wf, 
geo-between_wf, 
geo-point_wf, 
geo-congruent-iff-length, 
geo-between-symmetry, 
geo-strict-between-implies-between, 
subtype_rel_self, 
geo-between-outer-trans, 
geo-strict-between-sep3, 
geo-between-exchange4, 
geo-between-sep, 
geo-sep-or, 
geo-sep_wf, 
geo-three-segment, 
geo-colinear-cases, 
basic-geometry-_wf, 
stable__geo-between, 
geo-eq_wf, 
istype-void, 
geo-between_functionality, 
geo-eq_weakening, 
geo-congruent-symmetry, 
geo-congruent-sep, 
geo-between-congruent, 
geo-between-inner-trans, 
geo-between-exchange3, 
geo-construction-unicity, 
geo-add-length-between, 
geo-add-length_wf, 
squash_wf, 
true_wf, 
geo-length-type_wf, 
congruence-preserves-between_symmetric-points
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
because_Cache, 
hypothesisEquality, 
independent_functionElimination, 
applyEquality, 
hypothesis, 
instantiate, 
isectElimination, 
independent_isectElimination, 
sqequalRule, 
productElimination, 
rename, 
universeIsType, 
inhabitedIsType, 
equalitySymmetry, 
setElimination, 
dependent_set_memberEquality_alt, 
unionElimination, 
inrFormation_alt, 
voidElimination, 
functionIsType, 
lambdaEquality_alt, 
imageElimination, 
equalityTransitivity, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
inlFormation_alt
Latex:
\mforall{}e:BasicGeometry.  \mforall{}a,b,c,b',c':Point.
    (a\_b\_c  {}\mRightarrow{}  Colinear(a;c;c')  {}\mRightarrow{}  ab  \mcong{}  ab'  {}\mRightarrow{}  ac  \mcong{}  ac'  {}\mRightarrow{}  b'-a-b  {}\mRightarrow{}  (a\_b'\_c'  \mvee{}  a\_b\_c'))
Date html generated:
2019_10_16-PM-01_17_51
Last ObjectModification:
2019_02_16-PM-09_25_56
Theory : euclidean!plane!geometry
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