sentences:  These alternative sequences are in general canonically equivalent.The rules that define their sequencing in the canonical form also define whether they are considered to interact.Unicode provides code points for some characters or groups of characters which are modified only for aesthetic reasons (such as ligatures, the half-width katakana characters, or the double-width Latin letters for use in Japanese texts), or to add new semantics without losing the original one (such as digits in subscript or superscript positions, or the circled digits (such as "①") inherited from some Japanese fonts).