The section 19.639 table:expression in OpenDocument-v1.3-wd13-part3-documents-clean p.552 has as last sentence in third paragraph:

The XML namespace name bound to the namespace prefix specifies the syntax and semantics of the formulas and values occurring within the condition.

The word "condition" makes no sense here, likely a copy&paste error.

"expression" might work or "attribute value" instead of "condition".