Nuprl Lemma : base-member-per-function
∀[A:Type]. ∀[B:per-function(A;x.Type)]. ∀[f:Base].
  f ∈ per-function(A;x.B[x]) supposing ∀[a,a':Base].  (f a) = (f a') ∈ B[a] supposing a = a' ∈ A
Proof
Definitions occuring in Statement : 
per-function: per-function(A;a.B[a])
, 
uimplies: b supposing a
, 
uall: ∀[x:A]. B[x]
, 
so_apply: x[s]
, 
member: t ∈ T
, 
apply: f a
, 
base: Base
, 
universe: Type
, 
equal: s = t ∈ T
Definitions unfolded in proof : 
uall: ∀[x:A]. B[x]
, 
member: t ∈ T
, 
type-function: type-function{i:l}(A)
, 
uimplies: b supposing a
, 
function-eq: function-eq(A;a.B[a];f;g)
, 
per-function: per-function(A;a.B[a])
Lemmas referenced : 
per-function_wf_type, 
per-function-type-apply, 
per-function_wf, 
istype-universe, 
base_wf
Rules used in proof : 
sqequalSubstitution, 
sqequalTransitivity, 
computationStep, 
sqequalReflexivity, 
Error :isect_memberFormation_alt, 
cut, 
introduction, 
extract_by_obid, 
sqequalHypSubstitution, 
isectElimination, 
thin, 
hypothesisEquality, 
because_Cache, 
sqequalRule, 
Error :isectIsType, 
Error :inhabitedIsType, 
Error :equalityIsType4, 
hypothesis, 
equalityTransitivity, 
equalitySymmetry, 
baseApply, 
closedConclusion, 
baseClosed, 
Error :universeIsType, 
universeEquality, 
pertypeMemberEquality
Latex:
\mforall{}[A:Type].  \mforall{}[B:per-function(A;x.Type)].  \mforall{}[f:Base].
    f  \mmember{}  per-function(A;x.B[x])  supposing  \mforall{}[a,a':Base].    (f  a)  =  (f  a')  supposing  a  =  a'
Date html generated:
2019_06_20-AM-11_30_03
Last ObjectModification:
2018_10_06-AM-09_00_31
Theory : per!type
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