"Lengths refer to distance measurements and are denoted by <length> in the property definitions. A length is a dimension. However, for zero lengths the unit identifier is optional (i.e. can be syntactically represented as the <number> 0)."
"Lengths refer to distance measurements and are denoted by <length> in the property definitions. A length is a dimension. However, for zero lengths the unit identifier is optional (i.e. can be syntactically represented as the <number> 0)."