Nuprl Lemma : Euclid-Prop26-1
∀e:EuclideanPlane. ∀a,b,c,x,y,z:Point.
  (a # bc ⇒ x # yz ⇒ abc ≅a xyz ⇒ bac ≅a yxz ⇒ ab ≅ xy ⇒ (ac ≅ xz ∧ bc ≅ yz ∧ bca ≅a yzx))
Proof
Definitions occuring in Statement : 
geo-cong-angle: abc ≅a xyz, 
euclidean-plane: EuclideanPlane, 
geo-lsep: a # bc, 
geo-congruent: ab ≅ cd, 
geo-point: Point, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
and: P ∧ Q
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
and: P ∧ Q, 
cand: A c∧ B, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
subtype_rel: A ⊆r B, 
guard: {T}, 
uimplies: b supposing a, 
prop: ℙ, 
basic-geometry: BasicGeometry, 
euclidean-plane: EuclideanPlane, 
stable: Stable{P}, 
or: P ∨ Q, 
false: False, 
not: ¬A, 
geo-gt: cd > ab, 
squash: ↓T, 
exists: ∃x:A. B[x], 
geo-strict-between: a-b-c, 
geo-colinear-set: geo-colinear-set(e; L), 
l_all: (∀x∈L.P[x]), 
top: Top, 
int_seg: {i..j-}, 
lelt: i ≤ j < k, 
decidable: Dec(P), 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
select: L[n], 
cons: [a / b], 
subtract: n - m, 
geo-out: out(p ab), 
uiff: uiff(P;Q), 
geo-tri: Triangle(a;b;c)
Lemmas referenced : 
geo-congruent_wf, 
euclidean-plane-structure-subtype, 
euclidean-plane-subtype, 
subtype_rel_transitivity, 
euclidean-plane_wf, 
euclidean-plane-structure_wf, 
geo-primitives_wf, 
geo-cong-angle_wf, 
geo-lsep_wf, 
geo-point_wf, 
geo-ge-cases, 
stable__geo-congruent, 
double-negation-hyp-elim, 
geo-gt_wf, 
not_wf, 
istype-void, 
geo-congruent-sep, 
lsep-implies-sep, 
Error :geo-between-lt-angle, 
lsep-all-sym, 
lt-angle-not-cong2, 
euclidean-plane-axioms, 
geo-sep-sym, 
colinear-lsep, 
geo-colinear-is-colinear-set, 
geo-between-implies-colinear, 
length_of_cons_lemma, 
length_of_nil_lemma, 
decidable__le, 
full-omega-unsat, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
istype-int, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_wf, 
decidable__lt, 
intformless_wf, 
int_formula_prop_less_lemma, 
istype-le, 
istype-less_than, 
geo-cong-angle-symm2, 
geo-cong-angle-transitivity, 
geo-sas2, 
geo-strict-between-sep2, 
geo-between_wf, 
geo-out_weakening, 
geo-eq_weakening, 
cong-tri-implies-cong-angle2, 
geo-congruent-iff-length, 
geo-length-flip, 
out-preserves-angle-cong_1, 
p4geo
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
independent_pairFormation, 
hypothesis, 
universeIsType, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
applyEquality, 
instantiate, 
independent_isectElimination, 
sqequalRule, 
because_Cache, 
inhabitedIsType, 
dependent_functionElimination, 
setElimination, 
rename, 
unionEquality, 
independent_functionElimination, 
unionElimination, 
voidElimination, 
lambdaEquality_alt, 
functionIsType, 
unionIsType, 
imageElimination, 
productElimination, 
isect_memberEquality_alt, 
dependent_set_memberEquality_alt, 
natural_numberEquality, 
approximateComputation, 
dependent_pairFormation_alt, 
productIsType, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}a,b,c,x,y,z:Point.
    (a  \#  bc  {}\mRightarrow{}  x  \#  yz  {}\mRightarrow{}  abc  \mcong{}\msuba{}  xyz  {}\mRightarrow{}  bac  \mcong{}\msuba{}  yxz  {}\mRightarrow{}  ab  \mcong{}  xy  {}\mRightarrow{}  (ac  \mcong{}  xz  \mwedge{}  bc  \mcong{}  yz  \mwedge{}  bca  \mcong{}\msuba{}  yzx))
Date html generated:
2019_10_16-PM-02_35_35
Last ObjectModification:
2019_07_08-PM-02_03_47
Theory : euclidean!plane!geometry
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