Nuprl Lemma : not-less-implies-equal
∀x,y:ℤ.  (x = y ∈ ℤ) supposing ((¬x < y) and (¬y < x))
Proof
Definitions occuring in Statement : 
less_than: a < b
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
int: ℤ
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
not: ¬A
, 
rev_implies: P 
⇐ Q
, 
implies: P 
⇒ Q
, 
false: False
, 
prop: ℙ
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
subtype_rel: A ⊆r B
, 
top: Top
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
true: True
Lemmas referenced : 
decidable__int_equal, 
false_wf, 
not-equal-2, 
not-lt-2, 
add_functionality_wrt_le, 
add-swap, 
add-commutes, 
le-add-cancel, 
add-associates, 
not_wf, 
less_than_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
isect_memberFormation, 
introduction, 
cut, 
lemma_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
unionElimination, 
independent_pairFormation, 
voidElimination, 
productElimination, 
independent_functionElimination, 
independent_isectElimination, 
isectElimination, 
addEquality, 
natural_numberEquality, 
sqequalRule, 
applyEquality, 
lambdaEquality, 
isect_memberEquality, 
voidEquality, 
intEquality, 
because_Cache, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}x,y:\mBbbZ{}.    (x  =  y)  supposing  ((\mneg{}x  <  y)  and  (\mneg{}y  <  x))
Date html generated:
2016_05_13-PM-03_32_27
Last ObjectModification:
2015_12_26-AM-09_45_20
Theory : arithmetic
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