Nuprl Lemma : cons_cons_permr
∀T:Type. ∀a,a':T. ∀as,as':T List.  ((as ≡(T) as') ⇒ ([a; [a' / as]] ≡(T) [a'; [a / as']]))
Proof
Definitions occuring in Statement : 
permr: as ≡(T) bs, 
cons: [a / b], 
list: T List, 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
universe: Type
Definitions unfolded in proof : 
all: ∀x:A. B[x], 
implies: P ⇒ Q, 
member: t ∈ T, 
uall: ∀[x:A]. B[x], 
iff: P ⇐⇒ Q, 
and: P ∧ Q, 
rev_implies: P ⇐ Q, 
prop: ℙ
Lemmas referenced : 
permr_functionality_wrt_permr, 
cons_wf, 
permr_weakening, 
cons_functionality_wrt_permr, 
permr_inversion, 
hd_two_swap_permr, 
permr_wf, 
list_wf, 
istype-universe
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
lambdaFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
dependent_functionElimination, 
thin, 
hypothesisEquality, 
because_Cache, 
isectElimination, 
hypothesis, 
independent_functionElimination, 
productElimination, 
universeIsType, 
inhabitedIsType, 
instantiate, 
universeEquality
Latex:
\mforall{}T:Type.  \mforall{}a,a':T.  \mforall{}as,as':T  List.    ((as  \mequiv{}(T)  as')  {}\mRightarrow{}  ([a;  [a'  /  as]]  \mequiv{}(T)  [a';  [a  /  as']]))
 Date html generated: 
2020_05_20-AM-09_35_28
 Last ObjectModification: 
2020_01_08-PM-06_00_20
Theory : perms_2
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