d1: DISTANCE ATOMS=1,2
d2: DISTANCE ATOMS=2,4

r1: RESTRAINT ARG=d1 AT=0.0  KAPPA=1.0
r2: RESTRAINT ARG=d2 AT=0.0  KAPPA=1.0

SELECTOR NAME=s1 VALUE=0
SELECTOR NAME=s2 VALUE=1

sr1: SELECT ARG=r1.bias,r2.bias SELECTOR=s1
sr2: SELECT ARG=r1.bias,r2.bias SELECTOR=s2

PRINT ARG=r1.bias,r2.bias,sr1,sr2 FILE=COLVAR STRIDE=1
