Nuprl Lemma : less-iff-le
∀x,y:ℤ.  uiff(x < y;(1 + x) ≤ y)
Proof
Definitions occuring in Statement : 
less_than: a < b, 
uiff: uiff(P;Q), 
le: A ≤ B, 
all: ∀x:A. B[x], 
add: n + m, 
natural_number: $n, 
int: ℤ
Definitions unfolded in proof : 
prop: ℙ, 
uall: ∀[x:A]. B[x], 
false: False, 
implies: P ⇒ Q, 
not: ¬A, 
le: A ≤ B, 
member: t ∈ T, 
uimplies: b supposing a, 
and: P ∧ Q, 
uiff: uiff(P;Q), 
all: ∀x:A. B[x], 
rev_uimplies: rev_uimplies(P;Q), 
subtype_rel: A ⊆r B, 
squash: ↓T, 
cand: A c∧ B, 
less_than: a < b, 
or: P ∨ Q, 
true: True, 
less_than': less_than'(a;b), 
guard: {T}, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
top: Top, 
bfalse: ff, 
exists: ∃x:A. B[x], 
sq_type: SQType(T), 
bnot: ¬bb, 
ifthenelse: if b then t else f fi , 
assert: ↑b, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q
Lemmas referenced : 
le_wf, 
less_than_wf, 
less_than'_wf, 
le-iff-less-or-equal, 
int_subtype_base, 
equal-wf-base, 
lt_int_wf, 
eqtt_to_assert, 
assert_of_lt_int, 
istype-top, 
istype-void, 
eqff_to_assert, 
bool_subtype_base, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_wf, 
iff_transitivity, 
assert_wf, 
bnot_wf, 
not_wf, 
iff_weakening_uiff, 
assert_of_bnot, 
istype-assert, 
zero-add, 
le_reflexive, 
add_functionality_wrt_lt, 
less_than_transitivity1
Rules used in proof : 
intEquality, 
equalitySymmetry, 
equalityTransitivity, 
axiomEquality, 
hypothesis, 
natural_numberEquality, 
addEquality, 
isectElimination, 
extract_by_obid, 
voidElimination, 
hypothesisEquality, 
dependent_functionElimination, 
lambdaEquality, 
independent_pairEquality, 
thin, 
productElimination, 
sqequalHypSubstitution, 
sqequalRule, 
cut, 
introduction, 
isect_memberFormation, 
independent_pairFormation, 
lambdaFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
independent_isectElimination, 
lessCases, 
applyEquality, 
closedConclusion, 
baseApply, 
baseClosed, 
imageMemberEquality, 
inlFormation, 
inrFormation, 
lessDiscrete, 
Error :inhabitedIsType, 
Error :lambdaFormation_alt, 
unionElimination, 
equalityElimination, 
because_Cache, 
Error :isect_memberFormation_alt, 
axiomSqEquality, 
Error :isect_memberEquality_alt, 
Error :isectIsTypeImplies, 
imageElimination, 
independent_functionElimination, 
Error :dependent_pairFormation_alt, 
Error :equalityIsType4, 
promote_hyp, 
instantiate, 
cumulativity, 
Error :functionIsType, 
Error :equalityIsType1
Latex:
\mforall{}x,y:\mBbbZ{}.    uiff(x  <  y;(1  +  x)  \mleq{}  y)
Date html generated:
2019_06_20-AM-11_23_03
Last ObjectModification:
2018_10_16-PM-02_47_37
Theory : arithmetic
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