Nuprl Lemma : euclid-P3-ext
∀e:EuclideanPlane. ∀A,B,C1,C2:Point.  ∃E:Point. (A_E_B ∧ AE=C1C2) supposing (¬(C1 = C2 ∈ Point)) ∧ |C1C2| < |AB|
Proof
Definitions occuring in Statement : 
eu-lt: p < q, 
eu-length: |s|, 
eu-mk-seg: ab, 
euclidean-plane: EuclideanPlane, 
eu-between-eq: a_b_c, 
eu-congruent: ab=cd, 
eu-point: Point, 
uimplies: b supposing a, 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
not: ¬A, 
and: P ∧ Q, 
equal: s = t ∈ T
Definitions unfolded in proof : 
member: t ∈ T, 
euclid-P3, 
eu-extend-exists, 
eu-extend: (extend ab by cd), 
record-select: r.x, 
stable__eu-between-eq, 
uall: ∀[x:A]. B[x], 
so_lambda: so_lambda(x,y,z,w.t[x; y; z; w]), 
so_apply: x[s1;s2;s3;s4], 
top: Top, 
uimplies: b supposing a, 
strict4: strict4(F), 
and: P ∧ Q, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
has-value: (a)↓, 
prop: ℙ, 
guard: {T}, 
or: P ∨ Q, 
squash: ↓T, 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
eu-between-eq-def, 
eu-extend-property, 
sq_stable__eu-congruent, 
sq_stable__from_stable, 
stable__eu-congruent
Lemmas referenced : 
euclid-P3, 
lifting-strict-spread, 
has-value_wf_base, 
base_wf, 
is-exception_wf, 
eu-extend-exists, 
stable__eu-between-eq, 
eu-between-eq-def, 
eu-extend-property, 
sq_stable__eu-congruent, 
sq_stable__from_stable, 
stable__eu-congruent
Rules used in proof : 
introduction, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
cut, 
instantiate, 
extract_by_obid, 
hypothesis, 
sqequalRule, 
thin, 
sqequalHypSubstitution, 
isectElimination, 
baseClosed, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_isectElimination, 
independent_pairFormation, 
lambdaFormation, 
callbyvalueApply, 
baseApply, 
closedConclusion, 
hypothesisEquality, 
applyExceptionCases, 
inrFormation, 
imageMemberEquality, 
imageElimination, 
exceptionSqequal, 
inlFormation, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}e:EuclideanPlane.  \mforall{}A,B,C1,C2:Point.
    \mexists{}E:Point.  (A\_E\_B  \mwedge{}  AE=C1C2)  supposing  (\mneg{}(C1  =  C2))  \mwedge{}  |C1C2|  <  |AB|
Date html generated:
2016_10_26-AM-07_46_11
Last ObjectModification:
2016_08_29-PM-03_33_31
Theory : euclidean!geometry
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