They enjoy manipulating concrete objects, whether for practical or artistic purposes.

The designer makes convincing connections between abstract ideas and concrete objects.

Terminology aside, the essential point is that propositions are not concrete (or material) objects.

Relatively seen, there do exist concrete objects which we are aware of.

These are abstract entities of discourse, not concrete objects.

However, the type of a concrete object is known by the abstract factory.

A regular factory creates concrete objects of one type.

These are the concrete objects that make abstract communication possible.

No longer satisfied with establishing properties of concrete objects, mathematicians started to turn their attention to general theory.

Her approach is to use concrete objects and graphics, drawing "things" on the blackboard rather than just numbers, to help children understand mathematics.