Nuprl Lemma : ni-max-zero
∀[x:ℕ∞]. (ni-max(x;0∞) = x ∈ ℕ∞)
Proof
Definitions occuring in Statement : 
ni-max: ni-max(f;g), 
nat2inf: n∞, 
nat-inf: ℕ∞, 
uall: ∀[x:A]. B[x], 
natural_number: $n, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
nat: ℕ, 
le: A ≤ B, 
and: P ∧ Q, 
less_than': less_than'(a;b), 
false: False, 
not: ¬A, 
implies: P ⇒ Q, 
prop: ℙ, 
nat-inf: ℕ∞, 
squash: ↓T, 
so_lambda: λ2x.t[x], 
ge: i ≥ j , 
all: ∀x:A. B[x], 
decidable: Dec(P), 
or: P ∨ Q, 
uimplies: b supposing a, 
satisfiable_int_formula: satisfiable_int_formula(fmla), 
exists: ∃x:A. B[x], 
top: Top, 
so_apply: x[s], 
nat2inf: n∞, 
ni-max: ni-max(f;g), 
bool: 𝔹, 
unit: Unit, 
it: ⋅, 
btrue: tt, 
uiff: uiff(P;Q), 
bor: p ∨bq, 
ifthenelse: if b then t else f fi , 
bfalse: ff, 
sq_type: SQType(T), 
guard: {T}, 
bnot: ¬bb, 
assert: ↑b, 
iff: P ⇐⇒ Q, 
rev_implies: P ⇐ Q
Lemmas referenced : 
ni-max_wf, 
nat2inf_wf, 
false_wf, 
le_wf, 
all_wf, 
nat_wf, 
assert_wf, 
nat_properties, 
decidable__le, 
satisfiable-full-omega-tt, 
intformand_wf, 
intformnot_wf, 
intformle_wf, 
itermConstant_wf, 
itermAdd_wf, 
itermVar_wf, 
int_formula_prop_and_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_le_lemma, 
int_term_value_constant_lemma, 
int_term_value_add_lemma, 
int_term_value_var_lemma, 
int_formula_prop_wf, 
nat-inf_wf, 
bool_wf, 
eqtt_to_assert, 
btrue_wf, 
eqff_to_assert, 
equal_wf, 
bool_cases_sqequal, 
subtype_base_sq, 
bool_subtype_base, 
assert-bnot, 
iff_imp_equal_bool, 
lt_int_wf, 
bfalse_wf, 
intformless_wf, 
int_formula_prop_less_lemma, 
less_than_wf, 
assert_of_lt_int, 
iff_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
dependent_set_memberEquality, 
natural_numberEquality, 
sqequalRule, 
independent_pairFormation, 
lambdaFormation, 
hypothesis, 
applyLambdaEquality, 
setElimination, 
rename, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
lambdaEquality, 
functionEquality, 
applyEquality, 
functionExtensionality, 
addEquality, 
dependent_functionElimination, 
because_Cache, 
unionElimination, 
independent_isectElimination, 
dependent_pairFormation, 
int_eqEquality, 
intEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
computeAll, 
equalityElimination, 
equalityTransitivity, 
equalitySymmetry, 
productElimination, 
promote_hyp, 
instantiate, 
cumulativity, 
independent_functionElimination, 
addLevel, 
impliesFunctionality
Latex:
\mforall{}[x:\mBbbN{}\minfty{}].  (ni-max(x;0\minfty{})  =  x)
Date html generated:
2017_10_01-AM-08_29_56
Last ObjectModification:
2017_07_26-PM-04_24_14
Theory : basic
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