Nuprl Lemma : not-le-2
∀x,y:ℤ.  uiff(¬(x ≤ y);(y + 1) ≤ x)
Proof
Definitions occuring in Statement : 
uiff: uiff(P;Q)
, 
le: A ≤ B
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
add: n + m
, 
natural_number: $n
, 
int: ℤ
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
le: A ≤ B
, 
not: ¬A
, 
false: False
, 
prop: ℙ
, 
rev_implies: P 
⇐ Q
, 
subtype_rel: A ⊆r B
, 
top: Top
Lemmas referenced : 
iff_weakening_uiff, 
le_wf, 
less-iff-le, 
less_than'_wf, 
less_than_wf, 
uiff_wf, 
not_wf, 
not-le, 
add-commutes
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
cut, 
addLevel, 
sqequalHypSubstitution, 
productElimination, 
thin, 
independent_pairFormation, 
isect_memberFormation, 
introduction, 
independent_isectElimination, 
lemma_by_obid, 
isectElimination, 
because_Cache, 
addEquality, 
natural_numberEquality, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
dependent_functionElimination, 
sqequalRule, 
independent_pairEquality, 
lambdaEquality, 
voidElimination, 
cumulativity, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
intEquality, 
applyEquality, 
isect_memberEquality, 
voidEquality
Latex:
\mforall{}x,y:\mBbbZ{}.    uiff(\mneg{}(x  \mleq{}  y);(y  +  1)  \mleq{}  x)
Date html generated:
2016_05_13-PM-03_30_58
Last ObjectModification:
2015_12_26-AM-09_46_21
Theory : arithmetic
Home
Index