Checks and Balances: Presidential System of Government

Indeed, it is a fiction to talk of separation of powers in a presidential system as the three branches of government interact with one another in diverse ways in order to ensure the smooth operation of government. Such instances of cooperation or balancing acts are ironically examples of checks and balances.
Argentine Confederation

Argentine Confederation (1831 – 1861) | Argentina History

The Argentine Confederation was a union of Argentine provinces based on adherence to the Federal Pact. This alliance was in force from 1831 to 1861. The Confederacy was a weak union, in which there were no national laws or authorities, and in which each province maintained its sovereignty and governed itself.