Darśanas or Indian philosophical systems often take recourse to disputing the claims of other schools, to establish their own. In order to achieve this they have to resort to logic and reasoning, arguments and counter-arguments, pushing their opponent to a dead end or a vicious circle. Such positions are accepted as fallacious and hence invalidated.
Anyonyāśraya (mutual or reciprocal dependence) is one such defect. To illustrate: If the body is produced by karma, how is karma produced? By the body of course! Or, when I look at this pot and get the knowledge that this is a pot, how did I obtain it? By seeing it. How could I get that knowledge unless I had recognized it as a pot? That means, I must have already known it as a pot!
To sum up:
A situation in which a concept cannot be understood without reference to another which in turn cannot be understood without reference to the first, is a position of ‘anyonyāśraya’ or mutual dependence which is held to be a defect in reasoning.
Works on logic sometimes go into details or categorisation of this fallacy, which however do not add to our basic knowledge of the concept as such.