Scalar operations Node1 Scalar operations Node3 isnan:          test for NaN Node1->Node3 Node5 ladiv:          complex divide Node1->Node5 Node4 laisnan:        test for NaN, unoptimized Node1->Node4 Node6 lapy2:          robust sqrt( x^2 + y^2 ) Node1->Node6 Node7 lapy3:          robust sqrt( x^2 + y^2 + z^2 ) Node1->Node7 Node8 larmm:          scale factor to avoid overflow, step in latrs Node1->Node8 Node2 BLAS-like Node2->Node1 .