Nuprl Lemma : length-zero-implies-nil
∀l:Base. l ~ [] supposing ||l|| = 0 ∈ ℤ
Proof
Definitions occuring in Statement : 
length: ||as||
, 
nil: []
, 
uimplies: b supposing a
, 
all: ∀x:A. B[x]
, 
natural_number: $n
, 
int: ℤ
, 
base: Base
, 
sqequal: s ~ t
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
all: ∀x:A. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
uall: ∀[x:A]. B[x]
, 
nat: ℕ
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
decidable: Dec(P)
, 
or: P ∨ Q
, 
satisfiable_int_formula: satisfiable_int_formula(fmla)
, 
exists: ∃x:A. B[x]
, 
false: False
, 
implies: P 
⇒ Q
, 
not: ¬A
, 
top: Top
, 
and: P ∧ Q
, 
prop: ℙ
, 
sq_type: SQType(T)
, 
guard: {T}
, 
length: ||as||
, 
list_ind: list_ind, 
has-value: (a)↓
, 
cons: [a / b]
, 
label: ...$L... t
, 
ge: i ≥ j 
, 
nil: []
, 
it: ⋅
Lemmas referenced : 
bottom_diverge, 
has-value-implies-dec-isaxiom-2, 
int_term_value_add_lemma, 
itermAdd_wf, 
nat_properties, 
length-nat-if-has-value, 
length_of_cons_lemma, 
top_wf, 
has-value-implies-dec-ispair-2, 
base_wf, 
equal-wf-base, 
int_formula_prop_wf, 
int_formula_prop_eq_lemma, 
int_term_value_var_lemma, 
int_term_value_constant_lemma, 
int_formula_prop_le_lemma, 
int_formula_prop_not_lemma, 
int_formula_prop_and_lemma, 
intformeq_wf, 
itermVar_wf, 
itermConstant_wf, 
intformle_wf, 
intformnot_wf, 
intformand_wf, 
satisfiable-full-omega-tt, 
decidable__le, 
int-value-type, 
le_wf, 
set-value-type, 
nat_wf, 
value-type-has-value, 
subtype_rel_self, 
subtype_base_sq
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
instantiate, 
lemma_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
because_Cache, 
independent_isectElimination, 
hypothesis, 
sqequalRule, 
lambdaEquality, 
natural_numberEquality, 
hypothesisEquality, 
intEquality, 
dependent_set_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
dependent_functionElimination, 
unionElimination, 
dependent_pairFormation, 
int_eqEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality, 
independent_pairFormation, 
computeAll, 
independent_functionElimination, 
sqequalAxiom, 
baseApply, 
closedConclusion, 
baseClosed, 
callbyvalueCallbyvalue, 
callbyvalueReduce, 
callbyvalueAdd, 
productElimination, 
applyEquality, 
setElimination, 
rename, 
setEquality
Latex:
\mforall{}l:Base.  l  \msim{}  []  supposing  ||l||  =  0
Date html generated:
2016_05_14-AM-07_42_11
Last ObjectModification:
2016_01_15-AM-08_35_36
Theory : list_1
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