Nuprl Lemma : subtract-is-less
∀[x,y:ℤ].  uiff(x - y < x;0 < y)
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 : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
uimplies: b supposing a
, 
prop: ℙ
, 
all: ∀x:A. B[x]
, 
top: Top
, 
subtract: n - m
, 
subtype_rel: A ⊆r B
Lemmas referenced : 
less_than_wf, 
subtract_wf, 
member-less_than, 
add_functionality_wrt_lt, 
le_reflexive, 
add-associates, 
minus-one-mul, 
add-swap, 
add-mul-special, 
add-commutes, 
zero-mul, 
zero-add, 
minus-one-mul-top, 
add-zero
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
independent_pairFormation, 
hypothesis, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
natural_numberEquality, 
sqequalRule, 
productElimination, 
independent_pairEquality, 
isect_memberEquality, 
independent_isectElimination, 
because_Cache, 
equalityTransitivity, 
equalitySymmetry, 
intEquality, 
dependent_functionElimination, 
voidElimination, 
voidEquality, 
multiplyEquality, 
minusEquality, 
addEquality, 
applyEquality, 
lambdaEquality
Latex:
\mforall{}[x,y:\mBbbZ{}].    uiff(x  -  y  <  x;0  <  y)
Date html generated:
2016_05_13-PM-03_31_38
Last ObjectModification:
2015_12_26-AM-09_45_49
Theory : arithmetic
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