As a Riemann surface, this has genus 0, and every (level one) modular function is a rational function in j; in other words the field of modular functions is\\ mathbb (j).
This has genus 0. This is as a Riemann surface. Every (level one) modular function is a rational function in j. This is as a Riemann surface. The field of modular functions is\\ mathbb (j). This is in other words.