Nuprl Lemma : fpf-join-sub2
∀[A:Type]. ∀[B:A ⟶ Type]. ∀[eq:EqDecider(A)]. ∀[f1,g,f2:a:A fp-> B[a]].  (f1 ⊕ f2 ⊆ g) supposing (f2 ⊆ g and f1 ⊆ g)
Proof
Definitions occuring in Statement : 
fpf-join: f ⊕ g
, 
fpf-sub: f ⊆ g
, 
fpf: a:A fp-> B[a]
, 
deq: EqDecider(T)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
uimplies: b supposing a
, 
member: t ∈ T
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
so_lambda: λ2x.t[x]
, 
so_apply: x[s]
, 
prop: ℙ
, 
squash: ↓T
, 
true: True
, 
subtype_rel: A ⊆r B
, 
guard: {T}
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
rev_implies: P 
⇐ Q
, 
fpf-sub: f ⊆ g
, 
fpf-compatible: f || g
, 
top: Top
, 
cand: A c∧ B
Lemmas referenced : 
fpf-sub_witness, 
fpf-join_wf, 
fpf-sub_wf, 
fpf_wf, 
deq_wf, 
fpf-join-sub, 
equal_wf, 
squash_wf, 
true_wf, 
fpf-join-idempotent, 
iff_weakening_equal, 
assert_wf, 
fpf-dom_wf, 
subtype-fpf2, 
top_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
isect_memberFormation, 
introduction, 
cut, 
thin, 
sqequalHypSubstitution, 
dependent_functionElimination, 
hypothesisEquality, 
hypothesis, 
independent_functionElimination, 
extract_by_obid, 
isectElimination, 
sqequalRule, 
lambdaEquality, 
applyEquality, 
functionExtensionality, 
cumulativity, 
because_Cache, 
functionEquality, 
universeEquality, 
lambdaFormation, 
imageElimination, 
equalityTransitivity, 
equalitySymmetry, 
natural_numberEquality, 
imageMemberEquality, 
baseClosed, 
independent_isectElimination, 
productElimination, 
hyp_replacement, 
applyLambdaEquality, 
productEquality, 
isect_memberEquality, 
voidElimination, 
voidEquality
Latex:
\mforall{}[A:Type].  \mforall{}[B:A  {}\mrightarrow{}  Type].  \mforall{}[eq:EqDecider(A)].  \mforall{}[f1,g,f2:a:A  fp->  B[a]].
    (f1  \moplus{}  f2  \msubseteq{}  g)  supposing  (f2  \msubseteq{}  g  and  f1  \msubseteq{}  g)
Date html generated:
2018_05_21-PM-09_22_32
Last ObjectModification:
2018_02_09-AM-10_18_45
Theory : finite!partial!functions
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