Pacta sunt servanda - Agreements must be kept. Contracts are the law or contracts establish obligations (between those who sign them).⏎
Prior tempore potior iure - "Earlier in time, stronger in law". A legal principle that older laws take precedence over newer ones. Another name for this principle is lex posterior.⏎
Probatio vincit praesumptionem - Proof overcomes presumption.⏎