Bosons are described by tensor fields, which include scalar and vector fields as special cases. The other free parameter is the tensor to scalar ratio. Vector calculus concerns differentiation and integration of vector or scalar fields. Conjugation can be used to extract the scalar and vector parts of a quaternion. The difference is analogous to the difference between scalar and vector arithmetic. An analogy is the difference between scalar and vector arithmetic. Laplace's equation imposes that the Laplacian of a scalar field is zero. Suppose is a function taking as input a vector and outputting a scalar . Arrays are dimensioned by assigning to them as if they were a scalar variable. Therefore, SDPs are often formulated in terms of linear expressions on scalar products of vectors. The operation of multiplying a vector by a scalar is called "scalar multiplication". The vector Laplacian is similar to the scalar Laplacian. A hyperbolic estimate is better on average than scalar or linear estimates. Helium adds more than 150 scalar and vector instructions. Further simplification can be obtained by translation of axes and scalar multiplication.