J1CTWE and the tear choices are reversed. The resulting SIM is stored

by STOSIM. Should problems be encountered in restoring the SIM the

subprogram WRTDIR is invoked to terminate execution.

B.2.2 J1TWER

STOSIM (3.2), J1ADJT (4.1), J1LNKC (4.3), J1CTWE (5.2), J1DEGR (6.11)

 The subroutine J1TWER performs the two-way edge reduction for

ALWET. First JITWER examines the SIM to identify elements involved in

two-way edges. If none are found, the subroutine returns control to

ALWET. Otherwise, the rows and columns involved in the two-way edges

are linked together using the subroutine J1LNKC. When all two-way edges

are linked each is examined to determine which set of complement streams

should be torn. Choice of a stream which is not permitted to be torn

(previous untorn complement) causes a flag to be set and a return to

ALWET to be executed. After all tear choices are made, with the help

of the function J1CTWE to trace the two-way edge links, J1ADJT is

called. The SIM is stored by STOSIM in case any of the tear choices

should have to be reversed.


B.3 Level 3 Subprograms

B.3.1 ST0NDX

MEMSTR (4.4), CLRMEM (5.3)

 The subroutine STONDX stores the INDEX COMMON area, containing

all of the function and variable index information, into the MEMORY

COMM0N area. The function MEMSTR is invoked to determine the beginning

address in MEMIRY into which the data are to be loaded. If MEMSTR

indicates that there is insufficient space in )IE')Y, a call is made to

CLRMEM, in an attempt to create more space. The only part of each