Changes

Changes from Mercurial (hg https://foss.heptapod.net/isa-afp/afp-devel/ default)

Changeset 13908:ddcba483b350 by nipkow: adjusted T_sift_down: all primitives take 0 time.
The file was modified	`thys/Priority_Queue_Braun/Priority_Queue_Braun.thy`