In our chosen interpretation of exponential and logarithm, round- and Square-Brackets have an associated base that they implicitly share. The round-bracket ( ) contains exponents. The variable A in (A) is interpreted as an exponent while the round-bracket represents the arbitrary base, #A. Inversely, the square-bracket [ ] contains logarithmic content. The variable A in [A] is the form we are identifying the logarithm of, while the square-bracket represents the logarithmic function, log# A.
🔺
BRICKEN, William, 2019. Iconic Arithmetic Volume I: The Design of Mathematics for Human Understanding. Unary press. ISBN 978-1-73248-513-6, p. 190.