Mamata means mine. Mamata thaygam means letting go of the belief that it is mine, the sense of ownership.
Kartrutva thayagam refers to letting go of the thought that I am the doer.
Notes:
Some actions come with the belief that it is mine, claims of ownership.
The thought that I do my work or others are doing my work is known as mamata.
This work is mine and I shall take care of it with are inappropriate attitude.
These are all Bhagavan’s work, we are mere instruments for his work. This belief is called Mamata and Kartrutva thayagam.