Nuprl Lemma : int-prod-isolate
∀[n:ℕ]. ∀[m:ℕn]. ∀[f:ℕn ⟶ ℤ].  (Π(f[x] | x < n) = (Π(if (x =z m) then 1 else f[x] fi  | x < n) * f[m]) ∈ ℤ)
Proof
Definitions occuring in Statement : 
int-prod: Π(f[x] | x < k)
, 
int_seg: {i..j-}
, 
nat: ℕ
, 
ifthenelse: if b then t else f fi 
, 
eq_int: (i =z j)
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
function: x:A ⟶ B[x]
, 
multiply: n * m
, 
natural_number: $n
, 
int: ℤ
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
assert: ↑b
, 
bnot: ¬bb
, 
bfalse: ff
, 
ifthenelse: if b then t else f fi 
, 
btrue: tt
, 
it: ⋅
, 
unit: Unit
, 
bool: 𝔹
, 
less_than': less_than'(a;b)
, 
le: A ≤ B
, 
uiff: uiff(P;Q)
, 
so_apply: x[s]
, 
so_lambda: λ2x.t[x]
, 
guard: {T}
, 
sq_type: SQType(T)
, 
prop: ℙ
, 
top: Top
, 
false: False
, 
exists: ∃x:A. B[x]
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
uimplies: b supposing a
, 
or: P ∨ Q
, 
decidable: Dec(P)
, 
all: ∀x:A. B[x]
, 
ge: i ≥ j 
, 
nat: ℕ
, 
and: P ∧ Q
, 
lelt: i ≤ j < k
, 
int_seg: {i..j-}
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
rev_implies: P 
⇐ Q
, 
iff: P 
⇐⇒ Q
, 
subtype_rel: A ⊆r B
, 
true: True
, 
squash: ↓T
, 
nequal: a ≠ b ∈ T 
Lemmas referenced : 
nat_wf, 
neg_assert_of_eq_int, 
assert-bnot, 
bool_subtype_base, 
bool_cases_sqequal, 
equal_wf, 
eqff_to_assert, 
assert_of_eq_int, 
eqtt_to_assert, 
bool_wf, 
false_wf, 
add-member-int_seg1, 
le_wf, 
int_term_value_subtract_lemma, 
int_formula_prop_le_lemma, 
itermSubtract_wf, 
intformle_wf, 
decidable__le, 
int_seg_properties, 
subtract_wf, 
int_seg_wf, 
eq_int_wf, 
ifthenelse_wf, 
int_subtype_base, 
subtype_base_sq, 
lelt_wf, 
int_formula_prop_wf, 
int_term_value_constant_lemma, 
int_term_value_add_lemma, 
int_term_value_var_lemma, 
int_formula_prop_less_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_and_lemma, 
itermConstant_wf, 
itermAdd_wf, 
itermVar_wf, 
intformless_wf, 
intformnot_wf, 
intformand_wf, 
full-omega-unsat, 
decidable__lt, 
nat_properties, 
int-prod-split, 
iff_weakening_equal, 
btrue_wf, 
eq_int_eq_true, 
true_wf, 
squash_wf, 
zero-add, 
int-prod-single, 
int_formula_prop_eq_lemma, 
intformeq_wf, 
int_seg_subtype_nat, 
int-prod_wf, 
int_term_value_mul_lemma, 
itermMultiply_wf, 
decidable__equal_int
Rules used in proof : 
axiomEquality, 
functionEquality, 
promote_hyp, 
equalityElimination, 
lambdaFormation, 
functionExtensionality, 
applyEquality, 
equalitySymmetry, 
equalityTransitivity, 
cumulativity, 
instantiate, 
because_Cache, 
sqequalRule, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
intEquality, 
int_eqEquality, 
lambdaEquality, 
dependent_pairFormation, 
independent_functionElimination, 
approximateComputation, 
independent_isectElimination, 
unionElimination, 
natural_numberEquality, 
addEquality, 
dependent_functionElimination, 
hypothesis, 
independent_pairFormation, 
productElimination, 
dependent_set_memberEquality, 
rename, 
setElimination, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
cut, 
introduction, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
baseClosed, 
imageMemberEquality, 
universeEquality, 
imageElimination
Latex:
\mforall{}[n:\mBbbN{}].  \mforall{}[m:\mBbbN{}n].  \mforall{}[f:\mBbbN{}n  {}\mrightarrow{}  \mBbbZ{}].
    (\mPi{}(f[x]  |  x  <  n)  =  (\mPi{}(if  (x  =\msubz{}  m)  then  1  else  f[x]  fi    |  x  <  n)  *  f[m]))
Date html generated:
2018_05_21-PM-00_29_36
Last ObjectModification:
2017_12_10-PM-11_43_03
Theory : int_2
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