The line is completely electric, utilizing a 600V direct current system.

The line was electrified using the direct current system in 1923.

Every direct "ethical" system ever attempted froze or took too much time to make decisions.

Then the pair is called a direct system over .

Let be a direct system of objects and morphisms in (same definition as above).

The line was electrified using the third rail direct current system from 6 July 1930.

Under the direct system, land was levied by acre, without reference to value.

At the M' stage of the direct system, one has a rank n projection.

The direct current system did not have these drawbacks as of 1882, giving it significant advantages.

It is, after all, an inherently notational rather then a direct system.