No it’s not. The delegates are still there, uncommitted.
You’re assuming that Trump isn’t winning any.
And he would need to win 87% of those outstanding, outright.
He would need to win California, PA and NY to start.
Would you bet money that he would win any of the 3?
How about WA or OR?
Sorry, but there is no math based in reality that can get Cruz to 1237. He needs to win close to 90% of the remaining delegates to get there and in no universe based in reality will that happen.