Case of cryptic penned by syndicate of Guardian crossword setters arising (9)
I believe the answer is:
occurring
'guardian crossword setters arising' is the definition.
I can't judge whether this defines the answer.
'case of cryptic penned by syndicate' is the wordplay.
'case of' means to remove the middle letters (like emptying a case).
'penned' indicates putting letters inside (inserted letters are enclosed or penned in).
'by' becomes 'our' (I can't explain this - if you can you should give a lot more credence to this answer).
'syndicate' becomes 'ring' (I've seen this in another clue).
'cryptic' with its middle taken out is 'cc'.
'cc' going within 'our' is 'occur'.
'occur'+'ring'='OCCURRING'
'of' acts as a link.
Can you help me to learn more?