Problems with Minus

It’s common to write negatives using a “minus sign”, e.g. the negative of 5 as  − 5 and the negative of x as  − x. Here are some reasons I prefer the “bar” notation.

Minus Signs are Ambiguous

The minus sign has two common usages:

This is a reasonable distinction on its own, but causes problems when expressions involve multiple values and operations. Whilst these can be avoided using various conventions and workarounds, they make it harder to learn, harder to teach, harder to program into a computer (especially if we don’t want extra parentheses “just in case”!), etc.

For example:

Problems with Unary Minus

The usual way to indicate negatives is with a “minus sign” , but that notation can be confusing, and misses somenegatives by writing a lbar

things (where “positive” just means normal/standard/usual/everyday/etc.).

Problems with Binary Minux