busybox/shell/ash_test/ash-arith
..
arith1.sub
arith2.sub
arith_nested1.right
arith_nested1.tests
arith-bash1.right
arith-bash1.tests
arith-for.right
arith-for.testsx
arith-postinc.right
arith-postinc.tests
arith.right
arith.tests
README.ash

there is no support for (( )) constructs in ash