Nuprl Lemma : polymorphic-choice-int
∀f:⋂A:Type. (A ⟶ A ⟶ A). ((∀x,y:ℤ.  ((f x y) = x ∈ ℤ)) ∨ (∀x,y:ℤ.  ((f x y) = y ∈ ℤ)))
Proof
Definitions occuring in Statement : 
all: ∀x:A. B[x]
, 
or: P ∨ Q
, 
apply: f a
, 
isect: ⋂x:A. B[x]
, 
function: x:A ⟶ B[x]
, 
int: ℤ
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
or: P ∨ Q
, 
prop: ℙ
, 
implies: P 
⇒ Q
, 
squash: ↓T
, 
decidable: Dec(P)
, 
subtype_rel: A ⊆r B
, 
uimplies: b supposing a
, 
sq_type: SQType(T)
, 
guard: {T}
, 
label: ...$L... t
, 
true: True
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
not: ¬A
, 
false: False
, 
int_mod: ℤ_n
, 
so_lambda: λ2x y.t[x; y]
, 
so_apply: x[s1;s2]
, 
nat_plus: ℕ+
, 
less_than: a < b
, 
less_than': less_than'(a;b)
, 
modulus: a mod n
, 
int_seg: {i..j-}
, 
quotient: x,y:A//B[x; y]
, 
cand: A c∧ B
, 
absval: |i|
, 
exists: ∃x:A. B[x]
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
top: Top
Lemmas referenced : 
istype-universe, 
base_wf, 
or_wf, 
equal-wf-base, 
istype-base, 
decidable__equal_int, 
int_subtype_base, 
subtype_base_sq, 
subtype_rel_self, 
equal_wf, 
squash_wf, 
true_wf, 
iff_weakening_equal, 
istype-int, 
int-subtype-int_mod, 
int_mod_wf, 
quotient-member-eq, 
eqmod_wf, 
eqmod_equiv_rel, 
eqmod-zero, 
modulus-equal-iff-eqmod, 
istype-less_than, 
modulus_wf_int_mod, 
full-omega-unsat, 
intformeq_wf, 
itermConstant_wf, 
int_formula_prop_eq_lemma, 
istype-void, 
int_term_value_constant_lemma, 
int_formula_prop_wf, 
intformand_wf, 
itermVar_wf, 
int_formula_prop_and_lemma, 
int_term_value_var_lemma, 
exists-type-equating-ints, 
equal-wf-T-base, 
false_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :lambdaFormation_alt, 
cut, 
Error :isectIsType, 
instantiate, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
universeEquality, 
hypothesis, 
Error :functionIsType, 
Error :universeIsType, 
hypothesisEquality, 
because_Cache, 
setEquality, 
equalityTransitivity, 
equalitySymmetry, 
applyEquality, 
Error :inlFormation_alt, 
Error :equalityIstype, 
Error :inhabitedIsType, 
Error :dependent_set_memberEquality_alt, 
sqequalRule, 
Error :unionIsType, 
Error :inrFormation_alt, 
setElimination, 
rename, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
dependent_functionElimination, 
independent_functionElimination, 
closedConclusion, 
intEquality, 
natural_numberEquality, 
unionElimination, 
cumulativity, 
independent_isectElimination, 
Error :lambdaEquality_alt, 
productElimination, 
sqequalBase, 
voidElimination, 
independent_pairFormation, 
pertypeElimination, 
promote_hyp, 
Error :productIsType, 
callbyvalueReduce, 
sqleReflexivity, 
Error :dependent_pairFormation_alt, 
approximateComputation, 
Error :isect_memberEquality_alt, 
int_eqEquality, 
hyp_replacement, 
applyLambdaEquality, 
functionEquality
Latex:
\mforall{}f:\mcap{}A:Type.  (A  {}\mrightarrow{}  A  {}\mrightarrow{}  A).  ((\mforall{}x,y:\mBbbZ{}.    ((f  x  y)  =  x))  \mvee{}  (\mforall{}x,y:\mBbbZ{}.    ((f  x  y)  =  y)))
Date html generated:
2019_06_20-PM-02_44_31
Last ObjectModification:
2018_11_25-PM-01_33_30
Theory : num_thy_1
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