http://detexify.kirelabs.org/classify.html https://www.overleaf.com/project/5e882d9be7e96f0001793d46 https://en.wikipedia.org/wiki/Zermelo%E2%80%93Fraenkel_set_theory https://en.wikipedia.org/wiki/List_of_rules_of_inference \documentclass[letterpaper]{article} \usepackage[utf8]{inputenc} \usepackage……