Nuprl Lemma : geo-le-cases2
∀e:BasicGeometry. ∀[p,q:Length].  (¬¬((p < q ∨ q < p) ∨ (p = q ∈ Length)))
Proof
Definitions occuring in Statement : 
geo-lt: p < q
, 
geo-length-type: Length
, 
basic-geometry: BasicGeometry
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
or: P ∨ Q
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
geo-le: p ≤ q
, 
geo-lt: p < q
, 
exists: ∃x:A. B[x]
, 
squash: ↓T
, 
true: True
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
geo-eq: a ≡ b
, 
stable: Stable{P}
, 
guard: {T}
, 
or: P ∨ Q
, 
cand: A c∧ B
, 
uimplies: b supposing a
, 
so_apply: x[s1;s2]
, 
so_lambda: λ2x y.t[x; y]
, 
euclidean-plane: EuclideanPlane
, 
basic-geometry: BasicGeometry
, 
subtype_rel: A ⊆r B
, 
and: P ∧ Q
, 
quotient: x,y:A//B[x; y]
, 
prop: ℙ
, 
geo-length-type: Length
, 
false: False
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
Lemmas referenced : 
equal_wf, 
istype-universe, 
geo-between-trivial, 
quotient-member-eq, 
geo-eq_inversion, 
geo-sep-sym, 
geo-add-length-between, 
geo-length-equality, 
geo-add-length_wf, 
geo-length_wf, 
geo-mk-seg_wf, 
geo-le-same, 
geo-le_wf, 
squash_wf, 
true_wf, 
subtype_rel_self, 
iff_weakening_equal, 
minimal-not-not-excluded-middle, 
geo-eq_weakening, 
geo-between_functionality, 
minimal-double-negation-hyp-elim, 
not_wf, 
geo-sep_wf, 
stable__false, 
geo-length-type_wf, 
geo-primitives_wf, 
euclidean-plane-structure_wf, 
euclidean-plane_wf, 
basic-geometry_wf, 
subtype_rel_transitivity, 
basic-geometry-subtype, 
euclidean-plane-subtype, 
euclidean-plane-structure-subtype, 
istype-void, 
geo-lt_wf, 
geo-sep-O-X, 
geo-between-same-side2, 
geo-length-equiv, 
geo-eq_wf, 
geo-X_wf, 
geo-O_wf, 
geo-between_wf, 
geo-point_wf, 
subtype_quotient, 
false_wf
Rules used in proof : 
hyp_replacement, 
inlFormation_alt, 
inrFormation_alt, 
dependent_pairFormation_alt, 
dependent_set_memberEquality_alt, 
imageElimination, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
universeEquality, 
unionElimination, 
functionEquality, 
unionEquality, 
isectIsTypeImplies, 
isect_memberEquality_alt, 
functionIsTypeImplies, 
setIsType, 
applyLambdaEquality, 
instantiate, 
sqequalBase, 
productIsType, 
equalityIstype, 
unionIsType, 
functionIsType, 
voidElimination, 
universeIsType, 
independent_functionElimination, 
independent_pairFormation, 
independent_isectElimination, 
lambdaEquality_alt, 
rename, 
setElimination, 
dependent_functionElimination, 
because_Cache, 
applyEquality, 
hypothesisEquality, 
setEquality, 
isectElimination, 
inhabitedIsType, 
equalitySymmetry, 
equalityTransitivity, 
productElimination, 
promote_hyp, 
pertypeElimination, 
sqequalRule, 
hypothesis, 
extract_by_obid, 
pointwiseFunctionalityForEquality, 
sqequalHypSubstitution, 
thin, 
cut, 
introduction, 
isect_memberFormation_alt, 
lambdaFormation_alt, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mforall{}e:BasicGeometry.  \mforall{}[p,q:Length].    (\mneg{}\mneg{}((p  <  q  \mvee{}  q  <  p)  \mvee{}  (p  =  q)))
Date html generated:
2019_10_29-AM-09_15_01
Last ObjectModification:
2019_10_18-PM-03_25_04
Theory : euclidean!plane!geometry
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