Naturality of the value under pull-back of the list #
Kollár's functoriality for smooth morphisms [Kol07, 34.1] with the empty-blow-up convention
[Kol07, 32], for the value built from a list (valueOf): if T'' on the last stage of π^* L is
an empty extension of the pull-back of T' on the last stage of L along the last-stage lift
π_r (IsEmptyExtensionOfPullback), then the value built from π^* L and T'', read along ι,
is the value built from L and T', read along π ∘ ι. The input family BMO_{n,1} supplies
the two facts about its values that this needs — it is indifferent to empty members and commutes
with local analytic isomorphisms (IndifferentToEmptyMembers, CommutesWithLocalIsos, both
fields of the structure BMOanFam) — combined by seqOn_eq_of_isEmptyExtensionOfPullback; the
shrink-and-append step is handled by pullback_shrinkAppend_eraseEmpty, and the two reading
opens are compared by the input family's own compatibility clause (the image of the smaller
reading open lies in the larger one, image_pullbackLiftLast_liftRange_subset). Used by
Padding.lean for the canonicity of the shrinking chain.
The value of a family functor is compatible with an equality of triples.
The input family on an empty extension of a pull-back #
[Kol07, 34.1] with the empty-blow-up convention [Kol07, 32]: the value of BMO_{n,1} on a
triple T' that is an empty extension of the pull-back of T along a local analytic isomorphism
g is the pull-back of its value on T, read on the image open, with the empty rounds erased —
IndifferentToEmptyMembers (the extra empty members do not change the value) followed by
CommutesWithLocalIsos.
The value under pull-back of the list #
The value is natural under pull-back of the list ([Kol07, 34.1]; [Kol07, 32]): the value
built from π^* L and a triple T'' that is an empty extension of the pull-back of T' along the
last-stage lift π_r, read along ι, is the value built from L and T' read along π ∘ ι.