Nuprl Lemma : fset-image_functionality_wrt_subset
∀[T,A:Type]. ∀[eqt:EqDecider(T)]. ∀[eqa:EqDecider(A)]. ∀[f:T ⟶ A]. ∀[s1,s2:fset(T)].  f"(s1) ⊆ f"(s2) supposing s1 ⊆ s2
Proof
Definitions occuring in Statement : 
fset-image: f"(s)
, 
f-subset: xs ⊆ ys
, 
fset: fset(T)
, 
deq: EqDecider(T)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
f-subset: xs ⊆ ys
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
prop: ℙ
, 
uiff: uiff(P;Q)
, 
and: P ∧ Q
, 
rev_uimplies: rev_uimplies(P;Q)
, 
squash: ↓T
, 
exists: ∃x:A. B[x]
, 
cand: A c∧ B
, 
guard: {T}
Lemmas referenced : 
fset-member_witness, 
fset-image_wf, 
fset-member_wf, 
f-subset_wf, 
fset_wf, 
deq_wf, 
member-fset-image-iff, 
equal_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
sqequalHypSubstitution, 
lambdaFormation, 
extract_by_obid, 
isectElimination, 
thin, 
hypothesisEquality, 
cumulativity, 
functionExtensionality, 
applyEquality, 
hypothesis, 
independent_functionElimination, 
sqequalRule, 
lambdaEquality, 
dependent_functionElimination, 
isect_memberEquality, 
equalityTransitivity, 
equalitySymmetry, 
because_Cache, 
functionEquality, 
universeEquality, 
productElimination, 
independent_isectElimination, 
imageElimination, 
dependent_pairFormation, 
independent_pairFormation, 
promote_hyp, 
productEquality, 
imageMemberEquality, 
baseClosed
Latex:
\mforall{}[T,A:Type].  \mforall{}[eqt:EqDecider(T)].  \mforall{}[eqa:EqDecider(A)].  \mforall{}[f:T  {}\mrightarrow{}  A].  \mforall{}[s1,s2:fset(T)].
    f"(s1)  \msubseteq{}  f"(s2)  supposing  s1  \msubseteq{}  s2
Date html generated:
2017_04_17-AM-09_21_01
Last ObjectModification:
2017_02_27-PM-05_24_01
Theory : finite!sets
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