| A resident individual is allowed a credit against the tax |
| otherwise due under this Part, excluding the tax imposed by |
| section 5203-A, for the amount of income tax imposed on that |
| individual for the taxable year by another state of the United |
| States, a political subdivision of any such state, the District |
| of Columbia or any political subdivision of a foreign country |
| that is analogous to a state of the United States with respect to |
| income subject to tax under this Part that is derived from |
sources in that taxing jurisdiction also subject to tax under |
this Part. In determining whether income is derived from sources |
| in another jurisdiction, the assessor may not employ the law of |
| the other jurisdiction but shall instead assume that a statute |
| equivalent to section 5142 applies in that jurisdiction. The |
| credit, for any of the specified taxing jurisdictions, may not |
| exceed the proportion of the tax otherwise due under this Part, |
| excluding the tax imposed by section 5203-A, that the amount of |
| the taxpayer's Maine adjusted gross income derived from sources |
| in that taxing jurisdiction bears to the taxpayer's entire Maine |
adjusted gross income; provided except that, when a credit is |
| claimed for taxes paid to both a state and a political |
| subdivision of a state, the total credit allowable for those |
| taxes does not exceed the proportion of the tax otherwise due |
| under this Part, excluding the tax imposed by section 5203-A, |
| that the amount of the taxpayer's Maine adjusted gross income |
| derived from sources in the other state bears to the taxpayer's |
| entire Maine adjusted gross income. |