A <textual typebased block definition> or a <graphical typebased block definition> is transformed to a <block definition> which has the definitions of the block type as defined by <block type expression>. The number of derived <block definition>s is specified by <number of block instances>.
An <existing typebased block definition> can only appear in a subtype definition. It represents the block defined in the supertype of the subtype definition. Additional channels connected to gates of the existing block may be specified.