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
Home
Index