Data:L6a4/HOMFLYPT Polynomial

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle -a^2 z^2-z^2 a^{-2} +a^2 z^{-2} + a^{-2} z^{-2} +z^4+2 z^2-2 z^{-2} }