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.\"  * $Source: /vol/opua/opua2/sis/sis-1.1/common/src/sis/sis_lib/help/RCS/collapse.1,v $
.\"  * $Author: sis $
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.\"  * $Date: 1992/05/06 19:04:01 $
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.XX
collapse [n1] [n2]
.PP
Collapse nodes in the network.  With no arguments, the entire network is
collapsed into a single-level of functions (i.e., two-level form).  
Each output will be expressed in terms of the primary inputs.
.PP
Given a single node,
that function is collapsed until it is represented entirely in terms of
primary inputs.  
.PP
Given two arguments, it is assumed that the second node
is a fanin of the first node.  In this case, this dependency is removed
(the first node is expressed without the second node as a fanin).
.PP
Please note that this command negates any mapping that may have been done
at an earlier time.
.PP
Caution should be taken when collapsing network to two levels because
the two level representation may be too large.
The alternative is to use \fBeliminate\fR (selective collapse).
Refer to \fBeliminate\fR for the details.
