Nuprl Lemma : sorted-by-append1
∀[T:Type]. ∀[R:T ⟶ T ⟶ ℙ].  ∀x:T. ∀L:T List.  (sorted-by(R;L @ [x]) 
⇐⇒ sorted-by(R;L) ∧ (∀z∈L.R z x))
Proof
Definitions occuring in Statement : 
sorted-by: sorted-by(R;L)
, 
l_all: (∀x∈L.P[x])
, 
append: as @ bs
, 
cons: [a / b]
, 
nil: []
, 
list: T List
, 
uall: ∀[x:A]. B[x]
, 
prop: ℙ
, 
all: ∀x:A. B[x]
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
apply: f a
, 
function: x:A ⟶ B[x]
, 
universe: Type
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
all: ∀x:A. B[x]
, 
member: t ∈ T
, 
iff: P 
⇐⇒ Q
, 
and: P ∧ Q
, 
implies: P 
⇒ Q
, 
rev_implies: P 
⇐ Q
, 
subtype_rel: A ⊆r B
, 
so_lambda: λ2x.t[x]
, 
prop: ℙ
, 
so_apply: x[s]
, 
uimplies: b supposing a
, 
istype: istype(T)
, 
top: Top
, 
append: as @ bs
, 
so_lambda: so_lambda(x,y,z.t[x; y; z])
, 
so_apply: x[s1;s2;s3]
, 
guard: {T}
Lemmas referenced : 
sorted-by-reverse, 
sorted-by-cons, 
reverse-append, 
cons_wf, 
nil_wf, 
append_wf, 
sorted-by_wf, 
subtype_rel_dep_function, 
l_member_wf, 
l_all_wf, 
list_wf, 
istype-universe, 
reverse-cons, 
istype-void, 
reverse_nil_lemma, 
list_ind_nil_lemma, 
list_ind_cons_lemma, 
reverse_wf, 
l_all_iff, 
member-reverse
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
Error :lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
because_Cache, 
Error :lambdaEquality_alt, 
applyEquality, 
Error :inhabitedIsType, 
sqequalRule, 
hypothesis, 
productElimination, 
independent_functionElimination, 
dependent_functionElimination, 
independent_pairFormation, 
promote_hyp, 
Error :universeIsType, 
instantiate, 
cumulativity, 
functionEquality, 
universeEquality, 
setEquality, 
setElimination, 
rename, 
equalityTransitivity, 
equalitySymmetry, 
Error :setIsType, 
independent_isectElimination, 
Error :productIsType, 
Error :functionIsType, 
Error :isect_memberEquality_alt, 
voidElimination
Latex:
\mforall{}[T:Type].  \mforall{}[R:T  {}\mrightarrow{}  T  {}\mrightarrow{}  \mBbbP{}].
    \mforall{}x:T.  \mforall{}L:T  List.    (sorted-by(R;L  @  [x])  \mLeftarrow{}{}\mRightarrow{}  sorted-by(R;L)  \mwedge{}  (\mforall{}z\mmember{}L.R  z  x))
Date html generated:
2019_06_20-PM-01_45_05
Last ObjectModification:
2018_10_06-PM-11_56_11
Theory : list_1
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