Nuprl Lemma : rec-nat-induction
∀[P:ℕ ⟶ ℙ]. (∀[n:ℕ]. (P[n] 
⇒ P[n + 1])) 
⇒ (∀[n:ℕ]. P[n]) supposing Top ⊆r P[0]
Proof
Definitions occuring in Statement : 
nat: ℕ
, 
uimplies: b supposing a
, 
subtype_rel: A ⊆r B
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
prop: ℙ
, 
so_apply: x[s]
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
add: n + m
, 
natural_number: $n
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
subtype_rel: A ⊆r B
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
nat: ℕ
, 
all: ∀x:A. B[x]
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
not: ¬A
, 
rev_implies: P 
⇐ Q
, 
false: False
, 
uiff: uiff(P;Q)
, 
sq_stable: SqStable(P)
, 
squash: ↓T
, 
subtract: n - m
, 
top: Top
, 
le: A ≤ B
, 
less_than': less_than'(a;b)
, 
true: True
, 
ge: i ≥ j 
, 
guard: {T}
Lemmas referenced : 
equal_wf, 
subtract-add-cancel, 
minus-minus, 
less-iff-le, 
not-ge-2, 
subtract_wf, 
less_than_wf, 
ge_wf, 
less_than_irreflexivity, 
less_than_transitivity1, 
nat_properties, 
top_wf, 
subtype_rel_wf, 
le_wf, 
le-add-cancel, 
add-zero, 
add_functionality_wrt_le, 
add-commutes, 
add-swap, 
add-associates, 
minus-one-mul-top, 
zero-add, 
minus-one-mul, 
minus-add, 
condition-implies-le, 
sq_stable__le, 
not-le-2, 
false_wf, 
decidable__le, 
nat_wf, 
uall_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
introduction, 
sqequalRule, 
axiomEquality, 
hypothesis, 
thin, 
rename, 
lambdaFormation, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
lambdaEquality, 
functionEquality, 
applyEquality, 
because_Cache, 
hypothesisEquality, 
dependent_set_memberEquality, 
addEquality, 
setElimination, 
natural_numberEquality, 
dependent_functionElimination, 
unionElimination, 
independent_pairFormation, 
voidElimination, 
productElimination, 
independent_functionElimination, 
independent_isectElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
isect_memberEquality, 
voidEquality, 
intEquality, 
minusEquality, 
cumulativity, 
universeEquality, 
intWeakElimination, 
equalityTransitivity, 
equalitySymmetry
Latex:
\mforall{}[P:\mBbbN{}  {}\mrightarrow{}  \mBbbP{}].  (\mforall{}[n:\mBbbN{}].  (P[n]  {}\mRightarrow{}  P[n  +  1]))  {}\mRightarrow{}  (\mforall{}[n:\mBbbN{}].  P[n])  supposing  Top  \msubseteq{}r  P[0]
Date html generated:
2016_05_13-PM-04_02_53
Last ObjectModification:
2016_01_14-PM-07_24_38
Theory : int_1
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