rectification; Abhyankar-Sathaye embedding problem; variable Kronecker's Jugendtraum; elliptic functions; elliptic integrals; arithmetic of elliptic curves; Weierstrass \(\wp\)-function; projective plane cubics; Abel's theorem; inversion problem; Jacobi functions; theta functions; Lefschetz theorem; embeddings; theta identities; Euler identities; Jacobi substitutions; quadratic reciprocity; Siegel modular group; modular forms; Eisenstein series; modular equation; arithmetic subgroups; arithmetic applications; solvability of algebraic equations; Galois theory; Klein's icosaeder; quintic equation; imaginary quadratic number fields; class invariants; class polynomial; Mordell-Weil theorem 