Nuprl Lemma : mfun-strong-subtype
∀[X,Y:Type]. ∀[d:metric(X)]. ∀[d':metric(Y)]. ∀[A:Type].
  strong-subtype(FUN(X ⟶ A);FUN(X ⟶ Y)) supposing metric-subspace(Y;d';A)
Proof
Definitions occuring in Statement : 
metric-subspace: metric-subspace(X;d;A), 
mfun: FUN(X ⟶ Y), 
metric: metric(X), 
strong-subtype: strong-subtype(A;B), 
uimplies: b supposing a, 
uall: ∀[x:A]. B[x], 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x], 
uimplies: b supposing a, 
strong-subtype: strong-subtype(A;B), 
member: t ∈ T, 
metric-subspace: metric-subspace(X;d;A), 
and: P ∧ Q, 
subtype_rel: A ⊆r B, 
cand: A c∧ B, 
sq_stable: SqStable(P), 
implies: P ⇒ Q, 
squash: ↓T, 
exists: ∃x:A. B[x], 
prop: ℙ, 
mfun: FUN(X ⟶ Y), 
is-mfun: f:FUN(X;Y), 
all: ∀x:A. B[x], 
guard: {T}
Lemmas referenced : 
sq_stable__subtype_rel, 
mfun_wf, 
metric-on-subtype, 
mfun-subtype, 
equal_wf, 
is-mfun_wf, 
metric-subspace_wf, 
metric_wf, 
istype-universe, 
meq_weakening
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
productElimination, 
applyEquality, 
independent_isectElimination, 
hypothesis, 
sqequalRule, 
independent_functionElimination, 
imageMemberEquality, 
baseClosed, 
imageElimination, 
independent_pairFormation, 
setEquality, 
productEquality, 
lambdaEquality_alt, 
setElimination, 
rename, 
applyLambdaEquality, 
dependent_set_memberEquality_alt, 
universeIsType, 
because_Cache, 
setIsType, 
productIsType, 
equalityIstype, 
inhabitedIsType, 
instantiate, 
universeEquality, 
functionExtensionality, 
dependent_functionElimination, 
equalitySymmetry, 
equalityTransitivity, 
lambdaFormation_alt
Latex:
\mforall{}[X,Y:Type].  \mforall{}[d:metric(X)].  \mforall{}[d':metric(Y)].  \mforall{}[A:Type].
    strong-subtype(FUN(X  {}\mrightarrow{}  A);FUN(X  {}\mrightarrow{}  Y))  supposing  metric-subspace(Y;d';A)
Date html generated:
2019_10_30-AM-06_32_28
Last ObjectModification:
2019_10_02-AM-10_06_18
Theory : reals
Home
Index