These twenty-five tales from Geoff Nelder have increment as a theme. INCREMENT: For example a pothole doubles...
Noun - an increase or addition, especially one of a series on a fixed scale.
Synonyms: increase, addition, gain, augmentation, step up, supplement, addendum, adjunct, accretion, boost, enhancement.
Verb - cause a discrete increase in.
Mathematically the difference can be negative - decremental.