Topic: 開ける as an intransitive verb in expressing a lack of change
In the section about Expressing a lack of change the last example sentence is
窓が開けっ放しだったので、蚊がいっぱい入った.
But I thought that in the basic grammar section about transitive and intransitive verbs 「開ける」 was mentioned as a transitive verb and shouldn't it therefore be 「窓を開けっ放し...」?