# 
# This script computes all ternary one-element (co+)extensions of the given
# matroid set $param1.
# Those ones with branch-width 3 are written to ${param1}b for the next step.
# Those ones with branch-width 4 are written to ${param1}b-4, and those not having
# minor in the set  ${param1}-exc + bw3-reg-exc  are written to ${param1}b-4n
# and added to ${param1}b-exc.
# 
# All ternary non-binary non-whirl matroids can be obtained from the 3-whirl,
# see in [Oxley].
# (The first step generates a list of F7-, O7, P7, and their duals.)
# Notice that the 3-whirl is self-dual.
# 
# Call the procedure as  macek -pGF3 -g-1 '&bw3tern input' .
# 
@subd-param1 	"t6."
@sub-exclist 	${param1}-exc
@sub-exclistout ${param1}b-exc
@sub-excextra 	bw3-reg-exc

@sub-excluded 	 "((((S)(S)|"
@sub-excludedin  "((((1)("
@sub-excludedout "((((2)("
{
@name "bw3tern-w"
@comment "bw3tern working subframe:"
{
@name "exc-known"
@comment "the known excl minors - extra, smaller, new"
{ <$excextra }{ <$exclist }{ }
}{
@name extens1
@comment "new b-extensions of $input [${param1}]..."
}{
@name e-bwidth4
@comment "those generated with bwidth 4 get here:"
}{
@name e-bwidth4n
@comment "those new excl-minors with bwidth 4 get here:"
}{
@name e-bwidth3
@comment "those next with bwidth 3 get here:"
}}
@sub-input "(()(S))"
{
<$param1
@comment "this is the starting set of matroids ${param1}:"
}

!quiet
!prtree (T)
@sub-gener3  "(((4)("
@sub-generall  "(((1)("
@sub-gener4bw  "(((2)("
@sub-gener4n  "(((3)("
@extinherit ext-forbid

!extend b $input  >$generall(0t)|
!move ${generall}S|  >${gener3}(0t)|
!rex-bwidth3 ${gener3}S|
!move ^1  >${gener4bw}(0t)|

!writetreeto ${param1}b ${gener3}T|
!writetreeto ${param1}b-4 ${gener4bw}T|
!move ${gener4bw}S|  >$gener4n(0t)|
!filx-minor ${gener4n}s| $excluded
!writetreeto ${param1}b-4n ${gener4n}T|

!move ${excludedin}S| >$excludedout(0t)|
!move ${gener4n}S| >$excludedout(0t)|
!writetreeto ${param1}b-exc ${excludedout}T|
!writetreeto ${param1}b-all (T)
!prtree