dylan - mathematically, this use of increase is correct - to distinguish you would say strictly increasing if equal wasnt allowed.
However given the majority of listener solvers probably dont have a maths degree ( i dont remember doing this till analysis classes at university), i agree its a bit misleading.
i also think the preamble is misleading in another way also (well it sent me down wrong road initially).
Interesting that this was deemed to be acceptable by the editors.