right syntax of a trigger with double condition

I want to make a trigger that is execute on ly in case of 2 condition of the same record are verificate….but I don’t find the way with the syntax….
I tried with comma, +, nothing….but in everyone of these the formula ignore the first condition ['TODO.2' = 31] and consider only the second [CHIUSURA = null])

below an extract of the formula..
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let jj := cnt('3. Commissioni'.'Elenco Workflow (tutti)'['TODO.2' = 31],[CHIUSURA = null]);
…….
let result := dialog("COMPLETA WORKFLOW", "Confermi?", ["Si", "Annulla"]);
if result = "Si" and i = 31 and jj > 0 then
…..(something)