The McKinsey-Tarski theorem for locally compact ordered spaces Guram Bezhanishvili, Nick Bezhanishvili, Joel Lucero-Bryan, Jan van Mill Abstract: We prove that the modal logic of a crowded locally compact generalized ordered space is S4. This provides a version of the McKinsey-Tarski theorem for generalized ordered spaces. We then utilize this theorem to axiomatize the modal logic of an arbitrary locally compact generalized ordered space.