Declaring assumptions using assume() takes an awful lot of time, e.g.:
var('a b c d e f g h i')

The same applies to declaring variables with the domain option, e.g. var('a', domain='positive'). See also https://cocalc.com/projects/34b4b62a-2621-47c8-9bda-cde3a855f995/files/test_assumptions.ipynb for an example. Does anyone know why this takes so much time and/or how this could be made faster? Thanks a lot!