$14[Ib: Modularity and "Recipies" for cells]
$p1
The editor allows the user to create 
generalised descriptions of component structures
where subsequently they can be 
invoked with individual parameters for each instantiation.
$p1
The building blocks in circuit design are described both in terms of their
component structure and their geometric attributes, like size, shape and
orientation. For a
transistor we may have either an "etpx" (polysilicon in the x-direction)
or an "etpy" (polysilicon in the y-direction). Both these objects
share the same component structure but possess unique positioning parameters. 
We may think of an analogy
of a "recipe" which describes how to construct an object
and a list of "ingredients" which uniquely define each object type. By
partitioning the component description in this fashion it is possible to
perform geometric transformations such as scaling and rotation without
having to generate an entire component data structure each time. We merely
provide a new list of ingredients.
$Figure'Variations of a transistor "recipe"'
$b1 $h[Argument arrays and Indexing]
$p1
Nodes in the structure can obtain any of their two 16-bit arguments
through indexing into the current environmental argument array.
Execution flags $h[indexA] and $h[indexB] indicate whether
the first and the second half-word of the argument (possibly obtained
indirectly for $h[Pointer]=1) are the final arguments or indexes into
such array.
$p1
The array itself is declared by a node
$h[Setarguments](array pointer) where the new array pointer replaces
the one inherited from above for the subordinate subgraph of the declaration
node.
The construct provides the subgraphs which can be used like drawing
procedures in several places in the graph.
$p1
In the example above, the fixed-dimensions description of a transistor
from the previous page has been replaced by a "recipe" for a simple transistor,
where explicit dimensions have been replaced by indexes into a fixed-format
array. Various effects like rotation and size variations can be obtained
through appropriate swopping or variation of values in the individual
declarations of argument arrays prior to "calling" the transistor drawing graph.
$p1
The graph is no longer a tree, but it still remains acyclic.