Two Words: Between
This refers to research regarding the minimum number of single-character edits required to change one word into another.
In editing, a "paper" (proof) might need a vertical line or a "close up" symbol ( ∐coproduct of Between Two Words
A study of handwriting often focuses on maintaining uniform, single-space gaps between words, such as those seen in the work of Prakriti Malla . To help you better, I need to know: ? Are you researching computer science/string algorithms ? Are you asking about proofreading a manuscript ? [1103.4513] Remarks on separating words - arXiv This refers to research regarding the minimum number