double play
feed two birds with one scone
double-acting
kill two birds with one stone
come of
two for two
process
procedure
succeedant
goal
achievement
reavowal
efficacy
bistrategic
counterdecision
bifunctional
biformed
while one is at it
aftercoming
happy landings
in one foul swoop
pass
monoquantal
semisuccessfully
interresponse
duopolistically
notch up
as
programming
succedent
emulation
law of action and reaction
to
Newton's third law of motion
third law of motion
Newton's third law
termination
make one's own luck
relate
consolidation
effectiveness
twofoldly
response
doubly
bring to bear
swy
tweezer
when one's ship comes in
in two ways
procession