Nuprl Lemma : surject-nat-bool
∃g:ℕ ⟶ 𝔹. Surj(ℕ;𝔹;g)
Proof
Definitions occuring in Statement : 
surject: Surj(A;B;f)
, 
nat: ℕ
, 
bool: 𝔹
, 
exists: ∃x:A. B[x]
, 
function: x:A ⟶ B[x]
Definitions unfolded in proof : 
nequal: a ≠ b ∈ T 
, 
true: True
, 
not: ¬A
, 
less_than': less_than'(a;b)
, 
le: A ≤ B
, 
false: False
, 
assert: ↑b
, 
ifthenelse: if b then t else f fi 
, 
bnot: ¬bb
, 
guard: {T}
, 
sq_type: SQType(T)
, 
or: P ∨ Q
, 
prop: ℙ
, 
bfalse: ff
, 
uimplies: b supposing a
, 
and: P ∧ Q
, 
uiff: uiff(P;Q)
, 
btrue: tt
, 
it: ⋅
, 
unit: Unit
, 
bool: 𝔹
, 
implies: P 
⇒ Q
, 
all: ∀x:A. B[x]
, 
surject: Surj(A;B;f)
, 
nat: ℕ
, 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
exists: ∃x:A. B[x]
Lemmas referenced : 
equal-wf-T-base, 
neg_assert_of_eq_int, 
int_subtype_base, 
assert_of_eq_int, 
le_wf, 
false_wf, 
surject_wf, 
assert-bnot, 
bool_subtype_base, 
subtype_base_sq, 
bool_cases_sqequal, 
equal_wf, 
eqff_to_assert, 
eqtt_to_assert, 
nat_wf, 
btrue_wf, 
bfalse_wf, 
bool_wf, 
eq_int_wf, 
ifthenelse_wf
Rules used in proof : 
baseClosed, 
intEquality, 
independent_pairFormation, 
dependent_set_memberEquality, 
applyEquality, 
functionExtensionality, 
voidElimination, 
because_Cache, 
independent_functionElimination, 
equalitySymmetry, 
equalityTransitivity, 
cumulativity, 
instantiate, 
dependent_functionElimination, 
promote_hyp, 
independent_isectElimination, 
productElimination, 
equalityElimination, 
unionElimination, 
sqequalRule, 
lambdaFormation, 
natural_numberEquality, 
hypothesis, 
hypothesisEquality, 
rename, 
setElimination, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
lambdaEquality, 
dependent_pairFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution
Latex:
\mexists{}g:\mBbbN{}  {}\mrightarrow{}  \mBbbB{}.  Surj(\mBbbN{};\mBbbB{};g)
Date html generated:
2017_09_29-PM-05_48_02
Last ObjectModification:
2017_09_04-PM-00_14_35
Theory : fun_1
Home
Index