In what ways did early Jansenists believe that their doctrine of salvation differed from that of Calvinism?

The soteriology of [Jansenism](https://en.wikipedia.org/wiki/Jansenism) appears to bear some resemblance to that of Calvinism, as both emphasize doctrines like original sin, predestination, and irresistible grace. The two movements also share a common influence in Augustine, who was often quoted by their members. Another similarity is that both groups were ultimately regarded as heretical by Catholicism – the pope condemned Jansenism in 1653, despite claims by Jansenists that their views were *not* the same as those of Calvinists. Therein lies my question: In the years leading up to their condemnation, how did Jansenists argue that their views on soteriology, particularly original sin, predestination, and irresistible grace, were different from those of Calvinists?