Nuprl Lemma : AF-induction
∀[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].
  (∀[Q:T ⟶ ℙ]. TI(T;x,y.¬R[x;y];t.Q[t])) supposing 
     (AFx,y:T.R[x;y] and 
     (∀x,y,z:T.  ((¬R[x;y]) 
⇒ (¬R[y;z]) 
⇒ (¬R[x;z]))))
Proof
Definitions occuring in Statement : 
almost-full: AFx,y:T.R[x; y]
, 
TI: TI(T;x,y.R[x; y];t.Q[t])
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
not: ¬A
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
false: False
, 
so_apply: x[s1;s2]
, 
subtype_rel: A ⊆r B
, 
prop: ℙ
, 
almost-full: AFx,y:T.R[x; y]
, 
squash: ↓T
, 
TI: TI(T;x,y.R[x; y];t.Q[t])
, 
so_lambda: λ2x y.t[x; y]
, 
consistent-seq: R-consistent-seq(n)
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
exists: ∃x:A. B[x]
, 
seq-add: s.x@n
, 
AF-spread-law: AF-spread-law(x,y.R[x; y])
, 
isl: isl(x)
, 
outl: outl(x)
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
int_seg: {i..j-}
, 
nat: ℕ
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
cand: A c∧ B
, 
true: True
, 
bfalse: ff
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
iff: P 
⇐⇒ Q
, 
rev_implies: P 
⇐ Q
, 
lelt: i ≤ j < k
, 
le: A ≤ B
, 
decidable: Dec(P)
, 
less_than': less_than'(a;b)
, 
subtract: n - m
, 
sq_stable: SqStable(P)
, 
top: Top
, 
less_than: a < b
Lemmas referenced : 
not_wf, 
nat_wf, 
AF-spread-law_wf, 
AFbar_wf, 
basic_strong_bar_induction, 
unit_wf2, 
all_wf, 
consistent-seq_wf, 
decidable__AFbar, 
at_AFbar, 
AF-path-barred, 
almost-full_wf, 
eq_int_wf, 
bool_wf, 
eqtt_to_assert, 
assert_of_eq_int, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
iff_transitivity, 
assert_wf, 
bnot_wf, 
iff_weakening_uiff, 
assert_of_bnot, 
outl_wf, 
decidable__lt, 
false_wf, 
not-lt-2, 
not-equal-2, 
add_functionality_wrt_le, 
add-swap, 
add-commutes, 
le-add-cancel, 
less-iff-le, 
condition-implies-le, 
add-associates, 
minus-add, 
minus-one-mul, 
minus-one-mul-top, 
zero-add, 
le-add-cancel2, 
int_seg_wf, 
true_wf, 
decidable__le, 
not-le-2, 
sq_stable__le, 
add-zero, 
le_wf, 
seq-add_wf, 
set_wf, 
and_wf, 
less_than_wf, 
less_than_transitivity1, 
less_than_irreflexivity
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
introduction, 
sqequalRule, 
sqequalHypSubstitution, 
lambdaEquality, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
voidElimination, 
applyEquality, 
functionExtensionality, 
cumulativity, 
hypothesis, 
universeEquality, 
extract_by_obid, 
isectElimination, 
rename, 
imageElimination, 
imageMemberEquality, 
baseClosed, 
functionEquality, 
lambdaFormation, 
because_Cache, 
unionEquality, 
equalityTransitivity, 
equalitySymmetry, 
setEquality, 
setElimination, 
inlEquality, 
independent_functionElimination, 
dependent_set_memberEquality, 
unionElimination, 
equalityElimination, 
productElimination, 
independent_isectElimination, 
int_eqReduceTrueSq, 
natural_numberEquality, 
independent_pairFormation, 
dependent_pairFormation, 
promote_hyp, 
instantiate, 
intEquality, 
impliesFunctionality, 
int_eqReduceFalseSq, 
addEquality, 
minusEquality, 
isect_memberEquality, 
voidEquality, 
productEquality
Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    (\mforall{}[Q:T  {}\mrightarrow{}  \mBbbP{}].  TI(T;x,y.\mneg{}R[x;y];t.Q[t]))  supposing 
          (AFx,y:T.R[x;y]  and 
          (\mforall{}x,y,z:T.    ((\mneg{}R[x;y])  {}\mRightarrow{}  (\mneg{}R[y;z])  {}\mRightarrow{}  (\mneg{}R[x;z]))))
Date html generated:
2017_04_14-AM-07_27_57
Last ObjectModification:
2017_02_27-PM-02_57_29
Theory : bar-induction
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