Nuprl Lemma : FOL-subst-abstract
The evidence that fmla[x/y] in Dom, S, a is the same as the evidence
that fmla is true in Dom, S, a[y := a x].⋅
∀[Dom:Type]. ∀[S:FOStruct+{i:l}(Dom)]. ∀[fmla:mFOL()]. ∀[x,y:ℤ]. ∀[a:FOAssignment(mFOL-freevars(fmla[x/y]),Dom)].
  (Dom,S,a +|= FOL-abstract(fmla[x/y]) = Dom,S,a[y := a x] +|= FOL-abstract(fmla) ∈ ℙ)
Proof
Definitions occuring in Statement : 
FOL-subst: fmla[nw/old]
, 
FOL-abstract: FOL-abstract(fmla)
, 
mFOL-freevars: mFOL-freevars(fmla)
, 
mFOL: mFOL()
, 
FOSatWith+: Dom,S,a +|= fmla
, 
update-assignment: a[x := v]
, 
FOStruct+: FOStruct+{i:l}(Dom)
, 
FOAssignment: FOAssignment(vs,Dom)
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
apply: f a
, 
int: ℤ
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
FOL-subst: fmla[nw/old]
, 
all: ∀x:A. B[x]
, 
subtype_rel: A ⊆r B
, 
so_lambda: λ2x.t[x]
, 
and: P ∧ Q
, 
prop: ℙ
, 
uimplies: b supposing a
, 
squash: ↓T
, 
true: True
, 
so_apply: x[s]
, 
implies: P 
⇒ Q
, 
uiff: uiff(P;Q)
, 
FOAssignment: FOAssignment(vs,Dom)
, 
update-assignment: a[x := v]
, 
bool: 𝔹
, 
unit: Unit
, 
it: ⋅
, 
btrue: tt
, 
iff: P 
⇐⇒ Q
, 
ifthenelse: if b then t else f fi 
, 
bfalse: ff
, 
exists: ∃x:A. B[x]
, 
or: P ∨ Q
, 
sq_type: SQType(T)
, 
guard: {T}
, 
bnot: ¬bb
, 
assert: ↑b
, 
false: False
, 
rev_implies: P 
⇐ Q
, 
cand: A c∧ B
, 
nequal: a ≠ b ∈ T 
, 
not: ¬A
Lemmas referenced : 
FOL-rename-bound-to-avoid_wf, 
cons_wf, 
nil_wf, 
set_wf, 
mFOL_wf, 
equal_wf, 
list_wf, 
mFOL-freevars_wf, 
length_wf, 
FOL-abstract_wf, 
subtype_rel-equal, 
AbstractFOFormula+_wf, 
l_disjoint_wf, 
mFOL-boundvars_wf, 
l_disjoint_singleton2, 
FOAssignment_wf, 
mFOL-rename_wf, 
FOL-subst_wf, 
FOStruct+_wf, 
deq-member_wf, 
int-deq_wf, 
bool_wf, 
eqtt_to_assert, 
assert-deq-member, 
eq_int_wf, 
assert_of_eq_int, 
l_member_wf, 
eqff_to_assert, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
neg_assert_of_eq_int, 
mFOL-freevars-of-rename, 
equal-wf-base, 
int_subtype_base, 
not_wf, 
FOL-abstract-rename, 
squash_wf, 
true_wf, 
FOSatWith+_wf, 
list_subtype_base
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
hypothesisEquality, 
isectElimination, 
intEquality, 
hypothesis, 
instantiate, 
applyEquality, 
lambdaEquality, 
cumulativity, 
universeEquality, 
sqequalRule, 
productEquality, 
applyLambdaEquality, 
because_Cache, 
independent_isectElimination, 
imageElimination, 
equalitySymmetry, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
lambdaFormation, 
setElimination, 
rename, 
productElimination, 
equalityTransitivity, 
independent_functionElimination, 
isect_memberEquality, 
axiomEquality, 
functionExtensionality, 
unionElimination, 
equalityElimination, 
dependent_set_memberEquality, 
dependent_pairFormation, 
promote_hyp, 
voidElimination, 
inlFormation, 
independent_pairFormation, 
inrFormation, 
setEquality, 
hyp_replacement
Latex:
\mforall{}[Dom:Type].  \mforall{}[S:FOStruct+\{i:l\}(Dom)].  \mforall{}[fmla:mFOL()].  \mforall{}[x,y:\mBbbZ{}].
\mforall{}[a:FOAssignment(mFOL-freevars(fmla[x/y]),Dom)].
    (Dom,S,a  +|=  FOL-abstract(fmla[x/y])  =  Dom,S,a[y  :=  a  x]  +|=  FOL-abstract(fmla))
Date html generated:
2018_05_21-PM-10_24_39
Last ObjectModification:
2017_07_26-PM-06_38_37
Theory : minimal-first-order-logic
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