Is it possible to do a case conversion and search a string for a substring in one step?

For example, I have tested:

for each title in Books  [Title.contains(input.Title_search)]  - works but is case sensitive.

for each title in Books  [Title.contains(input.Title_search.toLowerCase())] - substring is converted to lower case successfully but obviously I need to convert the Title string as well.

for each title in Books  [Title.toLowerCase().contains(input.Title_search.toLowerCase()] - problem with syntax.

for each title in Books  [(Title.contains(input.Title_search.toLowerCase()).toLowerCase())] - problem with syntax.

This seems like it should be easy.  What am I missing?

Thanks in advance.

John