Baba Is You - Infinite Loops
The four infinite loop rules in Baba Is You. The infinite loop screen is triggered by the game trying to process too many rules in a turn. Things other than infinite loops can cause that, but these are all simple truly infinite loops that cause it. These are all caused by the Word block specifically causing the game to reprocess rules.
The first 3 cases are "rock Conditional Rock Is Word". When a rule like this is formed, the game initially just sees "Rock Is Word". This turns the rock at the front into text as far as the game is concerned. This makes the rule "Rock Conditional Rock Is Word" which itself turns off "Rock Is Word", as the game doesn't process rules internal to active rules without overlapping text. With "Rock Is Word" off however, the rock is no longer treated as text, so "Rock Conditional Rock Is Word" breaks and "Rock Is Word" reactivates, placing you back at the start of the loop.
The 4th case is using a similar principle, but instead of turning off "Rock Is Word" by putting it inside of another rule, it is instead directly turned off by "rock Is Not Word", which becomes "Rock Is Not Word" by the activation of the initial rule.