package prbnmcn-linalg

tensor m1 m2 is the parallel composition of m1 and m2

pullback_at_path m p s extends m to s by constructing a morphism equal to m at p and acting as the identity on s elsewhere.

• raises Dimensions_mismatch

  if range m is different from proj s p.

pullback_pointwise m s extends m to s by applying it pointwise to every position in

• raises Dimensions_mismatch

  if any rank one sub-tensor of s is different from range m.

sub ofs dom range constructs a morphism corresponding to the inclusion of dom, a rank-one tensor of dimension say m, into range, a rank-one tensor of dimension say n, such that the underlying positions of dom are mapped starting at index ofs in range.

Concretely, sub ofs dom range constructs a morphism mapping positions n in dom to positions n + ofs in range.

• raises Dimensions_mismatch

  if ofs <= 0 || dim dom <= 0 || ofs + dim dom > dim range.