==> logic/attribute.s <==
The attribute puzzle format is a traditional format in math education.
It occurs in logic materials developed in the sixties by EDC in Boston,
with visual objects. Example:

these are gloops: A B C D E 
these are not gloops: F G J L N
which of these are gloops? O P Q R S

Set#1
    with:  battery, key, yeast, bookmark
    w/out: stapler, match, Rubik's cube, pill bottle

Needs to be placed inside something else when used for its usual purpose.

Set#2
    with:  Rubik's cube, chess set, electrical wiring, compass needle
    w/out: clock, rope, tic-tac-toe, pencil sharpener

Uses color to distinguish between otherwise identical parts.

Set#3:
    with:  koosh, small intestine, Yorkshire Terrier, Christmas Tree
    w/out: toothbrush, oak chair, soccer ball, icicle

Villiform.