Entering d/dc abc predictably yields ab
Entering d/dc abcd predictably yields abd
However, entering d/dc abcde does not yield abde
How should I rephrase the text to get a correct result?
If with a freshly opened Wolframalpha.com you enter your equation with spaces between the variables it seems to work
but if you just click on the link it fails.
Using * between variables is also an option, but has the same work/not work issue.
Even re-evaluating the page again can sometimes make it switch between working and not working.