basic symbol
In computing, a fundamental symbol used in a character set, programming language, or notation system.
In this programming language, '+' and '-' are used as basic symbols.
記号 is a general term for any symbol or sign, while 基本記号 specifically refers to fundamental or elementary symbols, often in technical contexts.
Compound of 基本 (basic) and 記号 (symbol). The exact historical derivation is uncertain, but the term is a straightforward modern technical coinage.