You can try the following:
DEFINE ENVELOPE
1 3 TO 6 ENVELOPE 1 TYPE STRESS
1 3 TO 6 ENVELOPE 2 TYPE SERVICEABILITY
END DEFINE ENVELOPE
*
LOAD LIST ENV 1 2
*
PARAMETER 1
CODE AISC UNIFIED 2010
DFF 500 MEMB 3 TO 5 8
FYLD 248213 MEMB 3 TO 5 8
FU 413688 MEMB 3 TO 5 8
TRACK 2 ALL
CHECK CODE MEMB 3 TO 5 8
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