Two normally closed pushbuttons wired in parallel implement which logic?

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This question hinges on how normally closed contacts behave and how parallel wiring affects the combined logic. A normally closed pushbutton is closed (conducting) when it is not pressed, and it opens (stops conducting) when pressed. When two such NC buttons are wired in parallel, the path to the output is complete as long as at least one button is not pressed. The only time the path is broken is when both buttons are pressed, opening both contacts.

If we treat pressed as a logic input of 1, then not pressed is 0, and the circuit is conducting (output = 1) except when both inputs are 1 (both buttons pressed). That is the negation of an AND operation: output = NOT(A AND B). Therefore this wiring implements the NAND (Not And) function. The behavior wouldn’t match an AND or OR or NOR gate because those would require the output to follow the uninverted combination of inputs, whereas the NC contacts invert the inputs by default.