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.

ἡ ἐκ τοῦ κέντρου (οὖσα)‘radius’

Greek

References: Alm. Heiberg: I.10, 33:15-16, 34:8
Translated into:
Arabic: نصف القطر [Alm. MS Leiden: f. 6r]
Arabic: (مخرج) من المركز [Alm. MS Tunis: ?]
Modern translations:
English: radius, lit. the one drawn from the centre [Alm. Toomer: 49]
Synonyms:
διάστημα[Alm. Heiberg: I.10, 44:5]
ἡ ἐκ τοῦ κέντρου[PH Heiberg: I.8:1, 80:5; I.9:3, 82:12]