Nuprl Lemma : AF-induction-iff
∀T:Type. ∀R:T ⟶ T ⟶ ℙ.
  ((∀x,y:T.  Dec(R+[x;y]))
  ⇒ (∃R':T ⟶ T ⟶ ℙ. (AFx,y:T.R'[x;y] ∧ (∀x,y:T.  (R+[x;y] ⇒ (¬R'[x;y])))) ⇐⇒ ∀Q:T ⟶ ℙ. TI(T;x,y.R[x;y];t.Q[t])))
Proof
Definitions occuring in Statement : 
rel_plus: R+, 
almost-full: AFx,y:T.R[x; y], 
TI: TI(T;x,y.R[x; y];t.Q[t]), 
decidable: Dec(P), 
prop: ℙ, 
so_apply: x[s1;s2], 
so_apply: x[s], 
all: ∀x:A. B[x], 
exists: ∃x:A. B[x], 
iff: P ⇐⇒ Q, 
not: ¬A, 
implies: P ⇒ Q, 
and: P ∧ Q, 
function: x:A ⟶ B[x], 
universe: Type
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
member: t ∈ T, 
implies: P ⇒ Q, 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
uimplies: b supposing a, 
so_lambda: λ2x.t[x], 
so_apply: x[s], 
prop: ℙ, 
exists: ∃x:A. B[x], 
uall: ∀[x:A]. B[x], 
so_lambda: λ2x y.t[x; y], 
so_apply: x[s1;s2], 
not: ¬A, 
subtype_rel: A ⊆r B, 
false: False, 
rev_implies: P ⇐ Q, 
cand: A c∧ B, 
almost-full: AFx,y:T.R[x; y], 
nat: ℕ, 
decidable: Dec(P), 
or: P ∨ Q, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
top: Top, 
ge: i ≥ j , 
TI: TI(T;x,y.R[x; y];t.Q[t]), 
le: A ≤ B, 
less_than': less_than'(a;b), 
squash: ↓T, 
infix_ap: x f y, 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
eq_int: (i =z j), 
sq_type: SQType(T), 
guard: {T}, 
uiff: uiff(P;Q), 
true: True
Lemmas referenced : 
AF-induction4, 
almost-full_wf, 
rel_plus_wf, 
subtype_rel_self, 
istype-void, 
not_wf, 
TI_wf, 
decidable_wf, 
istype-universe, 
istype-nat, 
all_wf, 
nat_wf, 
equal_wf, 
decidable__le, 
full-omega-unsat, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
istype-int, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_wf, 
istype-le, 
squash_wf, 
exists_wf, 
nat_properties, 
intformand_wf, 
itermAdd_wf, 
itermVar_wf, 
int_formula_prop_and_lemma, 
int_term_value_add_lemma, 
int_term_value_var_lemma, 
istype-false, 
decidable__lt, 
intformless_wf, 
int_formula_prop_less_lemma, 
istype-less_than, 
rel_plus_iff2, 
eq_int_wf, 
intformeq_wf, 
int_formula_prop_eq_lemma, 
assert_wf, 
bnot_wf, 
equal-wf-base, 
set_subtype_base, 
le_wf, 
int_subtype_base, 
istype-assert, 
bool_cases, 
subtype_base_sq, 
bool_wf, 
bool_subtype_base, 
eqtt_to_assert, 
assert_of_eq_int, 
eqff_to_assert, 
iff_transitivity, 
iff_weakening_uiff, 
assert_of_bnot, 
rel-star-iff-rel-plus, 
true_wf, 
iff_weakening_equal, 
zero-add
Rules used in proof : 
cut, 
introduction, 
extract_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :lambdaFormation_alt, 
hypothesis, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
independent_pairFormation, 
independent_isectElimination, 
sqequalRule, 
Error :lambdaEquality_alt, 
applyEquality, 
Error :universeIsType, 
Error :functionIsType, 
universeEquality, 
Error :productIsType, 
Error :inhabitedIsType, 
isectElimination, 
because_Cache, 
instantiate, 
Error :dependent_pairFormation_alt, 
independent_functionElimination, 
voidElimination, 
functionExtensionality, 
functionEquality, 
cumulativity, 
Error :dependent_set_memberEquality_alt, 
natural_numberEquality, 
unionElimination, 
approximateComputation, 
Error :isect_memberEquality_alt, 
addEquality, 
setElimination, 
rename, 
int_eqEquality, 
imageElimination, 
productElimination, 
imageMemberEquality, 
baseClosed, 
Error :equalityIstype, 
Error :setIsType, 
applyLambdaEquality, 
equalityTransitivity, 
equalitySymmetry, 
closedConclusion, 
equalityElimination, 
hyp_replacement, 
intEquality, 
baseApply, 
sqequalBase
Latex:
\mforall{}T:Type.  \mforall{}R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}.
    ((\mforall{}x,y:T.    Dec(R\msupplus{}[x;y]))
    {}\mRightarrow{}  (\mexists{}R':T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}.  (AFx,y:T.R'[x;y]  \mwedge{}  (\mforall{}x,y:T.    (R\msupplus{}[x;y]  {}\mRightarrow{}  (\mneg{}R'[x;y]))))
          \mLeftarrow{}{}\mRightarrow{}  \mforall{}Q:T  {}\mrightarrow{}  \mBbbP{}.  TI(T;x,y.R[x;y];t.Q[t])))
Date html generated:
2019_06_20-PM-02_02_20
Last ObjectModification:
2018_12_07-PM-06_37_22
Theory : relations2
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