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.

خلاف‘variation’

Arabic

References: PH Morelon: I.2:3, 17:18
Translation of:
Greek: παραλλαγή [PH Heiberg: I.2:3, 72:23]
Modern translations:
French: contradiction [PH Morelon: I.2:3, 16:32]
German: abweichen (v) [PH Nix: I.2:3, 73:32]