UNIT-EXPRESSION ::= unit-expression UNIT-BINDING* UNIT-TERM UNIT-BINDING ::= unit-binding UNIT-NAME UNIT-SPEC
A unit expression with some unit bindings is written:
\ UN1:USP1; ...; UNn:USPn · UTThe sign displayed as the Greek letter lambda in LaTeX is input as `lambda'. The sign displayed as ` · ' may be input as `·' in ISO Latin-1, or as `.' in ASCII. When the list of unit bindings is empty, just the unit term `UT' is written.
It describes a composition of units declared (or defined) in the enclosing architectural specification. The result unit is a function, mapping the arguments specified by the unit bindings (if any) to the unit described by the unit term UT. The unit names UN1, ..., UNn for the arguments must be distinct, and not include the names of units previously declared in the enclosing architectural specification.
The unit bindings for the arguments (which are like unit declarations but with no possibility of importing other units) in a unit expression [CHANGED:] are for (non-parameterized) units that are required to build the result, but are not directly provided yet. This allows for compositions which express partial architectural specifications that depend on additional units, and might be used to instantiate the same composition for various realizations of the required units.