Delaware Code Title 30. State Taxes § 1125. Individual who is Delaware resident for part of year;  computation of tax

a. Such individual's modified Delaware source income (as otherwise determined under § 1122 of this title) for that period during which such individual was a resident of this State shall include all items of income, gain, loss and deduction whether or not derived from, or connected with, sources within this State;  and

b. The credit provided by § 1111 of this title shall be allowed;  provided that, however, for purposes of computing such credit, the amount of income taxes paid to another state shall be deemed to be limited by an amount which bears the same ratio to the total income taxes actually paid by such individual to such other state for such taxable year as the amount of Delaware adjusted gross income derived from sources within such other state (applying the rules of § 1124 of this title) while such individual was a resident of this State bears to the total Delaware adjusted gross income derived from sources within such other state (applying the rules of § 1124 of this title) for such taxable year.