Editing Crossword (section)

=== Fill-in crosswords ===
{{Main|Fill-In (puzzle)}}

A fill-in crossword (also known as crusadex or cruzadex) features a grid and the full list of words to be entered in that grid, but does not give explicit clues for where each word goes. The challenge is figuring out how to integrate the list of words together within the grid so that all intersections of words are valid. Fill-in crosswords may often have longer word length than regular crosswords to make the crossword easier to solve, and symmetry is often disregarded. Fitting together several long words is easier than fitting together several short words because there are fewer possibilities for how the long words intersect together. These types of crosswords are also used to demonstrate [[artificial intelligence]] abilities, such as finding solutions to the puzzle based on a set of determined [[constraint satisfaction problem|constraints]].<ref>{{cite book|last1=Poole|first1=David L.|last2=Mackworth|first2=Alan K.|date=2010|title=Artificial Intelligence: Foundations of Computational Agents|location=New York|publisher=Cambridge University Press|isbn=978-0-521-51900-7}}</ref>