PAL

Ptolemaeus Arabus et Latinus

_ (the underscore) is the placeholder for exactly one character.
% (the percent sign) is the placeholder for no, one or more than one character.
%% (two percent signs) is the placeholder for no, one or more than one character, but not for blank space (so that a search ends at word boundaries).

At the beginning and at the end, these placeholders are superfluous.

mathematics ‘mathematics’

English

References: Alm. Toomer: 35; 36. – TB Robbins: 125
Translation of:
Greek: μαθηματικὸν (γένος) [Alm. Heiberg: I.1, 5:9, 6:3]
Greek: μαθήματα [TB Robbins: 2:2, 57]