noun
opening square bracket; left square bracket
Refers specifically to the left or opening square bracket character '['. Used in technical, mathematical, and programming contexts.
数式では、左大括弧と右大括弧で範囲を囲む。
In mathematical expressions, you enclose a range with a left square bracket and a right square bracket.
配列のインデックスは左大括弧で始まる。
Array indices start with a left square bracket.
Compound of 左 (left) + 大括弧 (square bracket). The term is descriptive and transparent.