Nuprl Lemma : mk_deq_wf
∀[T:Type]. ∀[p:∀x,y:T.  Dec(x = y ∈ T)].  (mk_deq(p) ∈ EqDecider(T))
Proof
Definitions occuring in Statement : 
mk_deq: mk_deq(p), 
deq: EqDecider(T), 
decidable: Dec(P), 
uall: ∀[x:A]. B[x], 
all: ∀x:A. B[x], 
member: t ∈ T, 
universe: Type, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
member: t ∈ T, 
mk_deq: mk_deq(p), 
deq: EqDecider(T), 
all: ∀x:A. B[x], 
prop: ℙ, 
implies: P ⇒ Q, 
decidable: Dec(P), 
or: P ∨ Q, 
isl: isl(x), 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
false: False, 
not: ¬A, 
bfalse: ff, 
true: True, 
btrue: tt, 
ifthenelse: if b then t else f fi , 
assert: ↑b, 
so_apply: x[s], 
so_lambda: λ2x.t[x], 
subtype_rel: A ⊆r B
Lemmas referenced : 
istype-universe, 
decidable_wf, 
equal_wf, 
assert_wf, 
all_wf, 
true_wf, 
false_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
introduction, 
cut, 
sqequalHypSubstitution, 
hypothesis, 
sqequalRule, 
axiomEquality, 
equalityTransitivity, 
equalitySymmetry, 
Error :functionIsType, 
extract_by_obid, 
isectElimination, 
thin, 
hypothesisEquality, 
Error :inhabitedIsType, 
Error :universeIsType, 
Error :isect_memberEquality_alt, 
universeEquality, 
Error :dependent_set_memberEquality_alt, 
Error :lambdaEquality_alt, 
because_Cache, 
Error :lambdaFormation_alt, 
unionElimination, 
Error :equalityIsType1, 
dependent_functionElimination, 
independent_functionElimination, 
Error :productIsType, 
applyEquality, 
voidElimination, 
natural_numberEquality, 
independent_pairFormation, 
lemma_by_obid, 
lambdaEquality, 
lambdaFormation
Latex:
\mforall{}[T:Type].  \mforall{}[p:\mforall{}x,y:T.    Dec(x  =  y)].    (mk\_deq(p)  \mmember{}  EqDecider(T))
Date html generated:
2019_06_20-PM-00_31_53
Last ObjectModification:
2018_10_06-AM-11_20_18
Theory : equality!deciders
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