Nuprl Lemma : fpf-sub-val2
∀[A,A':Type].
  ∀[B:A ⟶ Type]
    ∀eq:EqDecider(A'). ∀f,g:a:A fp-> B[a]. ∀x:A'.
      ∀[P,Q:a:A ⟶ B[a] ⟶ ℙ].
        ((∀x:A. ∀z:B[x].  (P[x;z] 
⇒ Q[x;z])) 
⇒ z != f(x) ==> P[x;z] 
⇒ z != g(x) ==> Q[x;z] supposing g ⊆ f) 
  supposing strong-subtype(A;A')
Proof
Definitions occuring in Statement : 
fpf-sub: f ⊆ g
, 
fpf-val: z != f(x) ==> P[a; z]
, 
fpf: a:A fp-> B[a]
, 
deq: EqDecider(T)
, 
strong-subtype: strong-subtype(A;B)
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
so_apply: x[s1;s2]
, 
so_apply: x[s]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
so_apply: x[s1;s2]
, 
prop: ℙ
, 
subtype_rel: A ⊆r B
, 
so_apply: x[s]
, 
so_lambda: λ2x.t[x]
, 
all: ∀x:A. B[x]
, 
implies: P 
⇒ Q
, 
member: t ∈ T
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
top: Top
, 
pi1: fst(t)
, 
fpf-dom: x ∈ dom(f)
, 
fpf: a:A fp-> B[a]
, 
fpf-val: z != f(x) ==> P[a; z]
, 
rev_implies: P 
⇐ Q
, 
and: P ∧ Q
, 
iff: P 
⇐⇒ Q
, 
strong-subtype: strong-subtype(A;B)
, 
cand: A c∧ B
, 
list_ind: list_ind, 
reduce: reduce(f;k;as)
, 
deq-member: x ∈b L
, 
fpf-sub: f ⊆ g
, 
fpf-ap: f(x)
, 
pi2: snd(t)
Lemmas referenced : 
strong-subtype_wf, 
deq_wf, 
fpf_wf, 
all_wf, 
fpf-sub_wf, 
strong-subtype-deq-subtype, 
fpf-sub_witness, 
strong-subtype_witness, 
fpf_ap_pair_lemma, 
subtype_rel_list, 
assert-deq-member, 
strong-subtype-l_member-type, 
deq-member_wf, 
assert_wf, 
l_member_wf
Rules used in proof : 
universeEquality, 
functionEquality, 
independent_isectElimination, 
cumulativity, 
functionExtensionality, 
applyEquality, 
lambdaEquality, 
sqequalRule, 
because_Cache, 
lambdaFormation, 
rename, 
hypothesis, 
independent_functionElimination, 
hypothesisEquality, 
thin, 
isectElimination, 
sqequalHypSubstitution, 
extract_by_obid, 
introduction, 
cut, 
isect_memberFormation, 
sqequalReflexivity, 
computationStep, 
sqequalTransitivity, 
sqequalSubstitution, 
voidEquality, 
voidElimination, 
isect_memberEquality, 
dependent_functionElimination, 
productElimination, 
hyp_replacement, 
equalitySymmetry, 
applyLambdaEquality, 
equalityTransitivity, 
setEquality, 
dependent_set_memberEquality
Latex:
\mforall{}[A,A':Type].
    \mforall{}[B:A  {}\mrightarrow{}  Type]
        \mforall{}eq:EqDecider(A').  \mforall{}f,g:a:A  fp->  B[a].  \mforall{}x:A'.
            \mforall{}[P,Q:a:A  {}\mrightarrow{}  B[a]  {}\mrightarrow{}  \mBbbP{}].
                ((\mforall{}x:A.  \mforall{}z:B[x].    (P[x;z]  {}\mRightarrow{}  Q[x;z]))
                {}\mRightarrow{}  z  !=  f(x)  ==>  P[x;z]  {}\mRightarrow{}  z  !=  g(x)  ==>  Q[x;z]  supposing  g  \msubseteq{}  f) 
    supposing  strong-subtype(A;A')
Date html generated:
2020_05_20-AM-09_02_53
Last ObjectModification:
2020_01_07-PM-00_54_54
Theory : finite!partial!functions
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