Nuprl Lemma : finite-type-implies-finite
∀[T:Type]. ((∀x,y:T.  Dec(x = y ∈ T)) 
⇒ finite-type(T) 
⇒ finite(T))
Proof
Definitions occuring in Statement : 
finite: finite(T)
, 
finite-type: finite-type(T)
, 
decidable: Dec(P)
, 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
implies: P 
⇒ Q
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
exists: ∃x:A. B[x]
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
prop: ℙ
, 
nat: ℕ
Lemmas referenced : 
finite-type-equipollent, 
finite-type_wf, 
all_wf, 
decidable_wf, 
equal_wf, 
finite_functionality_wrt_equipollent, 
int_seg_wf, 
nsub_finite
Rules used in proof : 
cut, 
lemma_by_obid, 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
hypothesis, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
lambdaFormation, 
independent_functionElimination, 
productElimination, 
sqequalRule, 
lambdaEquality, 
universeEquality, 
natural_numberEquality, 
setElimination, 
rename, 
dependent_functionElimination
Latex:
\mforall{}[T:Type].  ((\mforall{}x,y:T.    Dec(x  =  y))  {}\mRightarrow{}  finite-type(T)  {}\mRightarrow{}  finite(T))
Date html generated:
2016_05_14-PM-04_05_29
Last ObjectModification:
2015_12_26-PM-07_41_38
Theory : equipollence!!cardinality!
Home
Index