there·up·on 
/ˈðerəˌpɑ:n/ adverb
/ˈðerəˌpɑ:n/ adverb formal 1 : immediately after that
▪ The committee reviewed the documents and thereupon decided to accept the proposal. 2 : on the thing that has been mentioned
▪ The jurors discussed the evidence and made/based their decision thereupon.
▪ The committee reviewed the documents and thereupon decided to accept the proposal.
▪ The jurors discussed the evidence and made/based their decision thereupon.
