In the first case the supposition is that the case is operable but the child inviable.
Their condition varies, but many are operable, or could easily be made so.
The Wrights' goal was an operable and reasonably lightweight unit to be obtained quickly and cheaply.
How could this principle be unified through all branches of science and reduced to an operable law?
In the second case the cancer is operable and the child is viable.
The case is not like that of the woman who has an operable cervical cancer while she is bearing an inviable fetus.
operable op·er·a·ble (ŏp'ər-ə-bəl, ŏp'rə-)
Being treatable by surgical operation with a reasonable degree of safety and chance of success.