We now return to the MDS of C and we see how all the other intervals are obtained.
Lowering a major interval by a half-step we get a minor interval.

Lets look at some examples. What is the interval between C and Eb? A third minor: at the E note (third step major) we removed a half-step to get Eb. What is the interval of C - Bb? One seventh minor, because we have also removed a half-step from B, seventh step (major).
If we lower the correct interval or its minor a half-step, we get a diminished interval.

unworkable

The double flat is created by removing a half-step from a note that is already flat, therefore Eb automatically becomes Ebb. Notice that Dbb in reality is a C, as Ebb is a D, etc. Remember that the note that is combined to the step must keep its name, to which the alterations must be added or removed. It is not possible to obtain the diminished I°.
The aumented interval is obtained by raising the correct interval or its major a half-step. What interval do we have between C and G#? A fifth increased interval, that we get by raising the fifth step (G) by a half-step (G#). Which interval separates C and D#? A second increased interval, obtained by increasing the second major (D) by a half-step (D#). The increased interval can also be called a surplus interval. The other two types of interval that we didn't mention are: the more than diminished interval, which is obtained by lowering the diminished interval a half-step, and the more than increased interval, which is obtained by raising the increased interval a half-step . The chart below is now complete.
 

unworkable