Errors and warnings

A line with a mistake shows its message in place of an answer and is underlined. Other lines keep working.

Message	Cause and fix
"x" isn't defined. Name it first: x = …	A typo, a note that mentions a defined name, or a label after a number (bread 1.20). Start notes with #; put names before =.
5 m and 3 kg are different kinds	Mixing dimensions with +, -, to, or a comparison.
"hours" refers to itself. Use another name	A name shadows a unit it uses (hours = 12.5 hours).
These lines depend on each other	Two or more names that refer to each other in a loop.
Nothing above to add up	A total with no numbers above it.
cannot divide 10 by zero	Division by zero.
expected Real(Length), got Integer(dimensionless)	A plain number where a unit is required. Add the unit.
Needs b != 0	A when guard rejected the call; the guard is quoted.
Not allowed: mod by zero	A built-in refused the value, with its reason.
These can't be combined	No operator takes these two kinds of value together.
To solve this, start with "solve for x:"	An equation written on its own, like 3x + 7 = 22.
Can't read this line	Syntax smoot cannot read, such as 2024-02-29 without @.
does not have enough information to solve for …	A formula was given too few properties.
the equation is inconsistent	Too many properties, and they disagree.
the solver cannot …	A shape the solver does not handle yet.

Warnings underline a line but still show an answer: a name declared twice, two numbers with no operator between them (2 3), an unused parameter, or an as that a following to discards.