# Revision history [back]

Besides the reported problem of series not being defined, there is one more: z is declared in multiple places as var('z') and K.<z> = FunctionField(QQ). Correspondingly, you try to expand t2 over powers the wrong z.

Workaround: replace t2.series(z, 23) with

z = t2.parent().gen()
SR(t2).taylor(z, 0, 23)


The definition var('z') becomes redundant and can be removed.

Besides the reported problem of series not being defined, there is one more: z is declared in multiple places as var('z') and K.<z> = FunctionField(QQ). Correspondingly, you try to expand t2 over the powers the of wrong z.

Workaround: replace t2.series(z, 23) with

z = t2.parent().gen()
SR(t2).taylor(z, 0, 23)


The definition var('z') becomes redundant and can be removed.

Besides the reported problem of series not being defined, there is one more: z is declared in multiple places as var('z') and K.<z> = FunctionField(QQ). Correspondingly, you try to expand t2 over the powers of wrong z.

Workaround: replace t2.series(z, 23) with

z = t2.parent().gen()
SR(t2).taylor(z, 0, 23)


The definition declaration var('z') becomes redundant and can be removed.

Besides the reported problem of series not being defined, there is one more: z is declared in multiple places as var('z') and K.<z> = FunctionField(QQ). Correspondingly, you try to expand t2 over the powers of wrong z.

Workaround: replace t2.series(z, 23) with

z = t2.parent().gen()
SR(t2).taylor(z, 0, 23)


The Also, while QuantumCartanMatrix gets z as an argument, it does not use but rather re-declares it. Correpondingly, the declaration var('z') becomes and submitting z and an argument to QuantumCartanMatrix are redundant and can be removed.