Nuprl Lemma : less-iff-positive
∀[x,y:ℤ].  uiff(x < y;0 < y - x)
Proof
Definitions occuring in Statement : 
less_than: a < b
, 
uiff: uiff(P;Q)
, 
uall: ∀[x:A]. B[x]
, 
subtract: n - m
, 
natural_number: $n
, 
int: ℤ
Definitions unfolded in proof : 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
prop: ℙ
, 
uall: ∀[x:A]. B[x]
, 
or: P ∨ Q
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
subtract: n - m
, 
top: Top
Lemmas referenced : 
less_than_wf, 
subtract_wf, 
member-less_than, 
add-monotonic, 
add-inverse, 
zero-add, 
add-associates, 
minus-one-mul, 
add-swap, 
add-commutes, 
add-mul-special, 
zero-mul
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
independent_pairFormation, 
isect_memberFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
hypothesis, 
natural_numberEquality, 
because_Cache, 
intEquality, 
sqequalRule, 
productElimination, 
independent_pairEquality, 
isect_memberEquality, 
independent_isectElimination, 
equalityTransitivity, 
equalitySymmetry, 
minusEquality, 
inlFormation, 
dependent_functionElimination, 
independent_functionElimination, 
voidElimination, 
voidEquality, 
multiplyEquality
Latex:
\mforall{}[x,y:\mBbbZ{}].    uiff(x  <  y;0  <  y  -  x)
Date html generated:
2019_06_20-AM-11_22_32
Last ObjectModification:
2018_08_17-PM-00_02_42
Theory : arithmetic
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