The expression for the compressible diagonal tau is (Hauke, 2001):

The piece of the code that implements it is:

Further, the expression for the non-diagonal version is (Hauke, 2001):

So that the implementation of the non-diagonal tau is:

The non-diagonal tau of 2019 is implemented as:

The algorithmic formulation of this version of tau (Bazilev et al., 2007) is:

The 2007 diagonal incompressible tau is implemented as follow:

The 2014 tau by Trelles, J. P., & Modirkhazeni, S. M. (2014) reads:

The coding for the 2014 tau version is:

The non-diagonal tau developed by Polner (2005) reads:

The corresponding implementation is:

The 1998 version of discontinuity capturing, one of the most rubost, is:

The piece of code implementing it is:

The 2006 version of the discontinuity capturing by Tezduyar & Senga (2006) reads:

The relative implementation follows:

The Galerking Least Square formulation for heat conduction is formulated as:

The corresponding implementation is: