A process declaration may be repeated any number of times as long as the port formal instances are equivalent.
Two port formal instance lists are equivalent if and only if the following are true:
Unlike C, where formal identifiers are optional in prototypes, port formal lists require names for each instance. This allows one to reference a process's ports individually before the process is defined.
Unlike normal instantiations found in a namespace or definition body, formal instance arrays may not be extended with re-declarations. Since they may only be declared once, they must be densely packed.