A PCAD (or "Pruned CAD") is a data-structure representing a
simplification of an existing QEPCAD CAD structure.
A PCAD cell C is a list of 4 objects,
(c,P,I,T), defined as follows:
- c is a QEPCAD cell structure. The cell represented
by c is
contained in the cell represented by C, and c is a section if and only if
C is a section.
- P is NULL if C is the root cell, and the
parent PCAD cell of C otherwise.
- I is defined as follows: I = 0 if C is
the root, and otherwise C is the Ith cell in the
stack over P, i.e. the stack index of C.
- T if C is a leaf cell, then T is
C's truth value. Otherwise, T is a list of
This structure is "defined" in the file
coarsecad.h in my private copy), which defines the
SC_CDTV, used with
LELTI to access c, P,
I, and T respectively.
Christopher W. Brown
Last modified: Fri Jan 22 16:19:25 EST 1999