p: POSITION ATOM=1

PRINT FILE=c1 ARG=p.*

UPDATE_IF ARG=p.x LESS_THAN=0.5 
PRINT FILE=c2 ARG=p.*
UPDATE_IF ARG=p.x END

PRINT FILE=c3 ARG=p.*

UPDATE_IF ARG=p.x LESS_THAN=0.5
UPDATE_IF ARG=p.y MORE_THAN=0.5
PRINT FILE=c4 ARG=p.*
UPDATE_IF ARG=p.y END
UPDATE_IF ARG=p.x END

UPDATE_IF ARG=p.x,p.y LESS_THAN=0.5,1000.0 MORE_THAN=-1000.0,0.5
PRINT FILE=c4b ARG=p.*

# at end of file all the blocks are implicitly closed
# thus next line is not necessary
# UPDATE_IF ARG=p.x,p.y END


