  This note is a complete library of symbolic parametrized expressions for both
real and complexified configuration spaces of a spherical 4-bar linkage.
Building upon the previous work from Izmestiev, (2016, Section 2), this library
expands on the expressions by incorporating all four folding angles across all
possible linkage length choices, along with the polynomial relation between
diagonals (spherical arcs). Furthermore, a complete MATLAB app script is
included, enabling visualization and parametrization. The derivations are
presented in a detailed manner, ensuring accessibility for researchers across
diverse disciplines.
