describes the fixed covariates, factors
and interactions including special functions to be included in the
ANOVA table,

generally begins with the reserved word
mu which fits a constant term, mean or intercept,

are listed BEFORE any random terms,

the combined size of primary fixed terms is controlled by the
!DENSE qualifier.

terms should be listed in a systematic Analysis of Variance
order if tests of fixed effects are required because of the way
ASReml generates
singularities.

Sparse fixed terms

The !f
sparse_{f}xed terms in model formula

are the fixed covariates (for example,
the fixed lin(row) covariate now included in the model formula below), factors and
interactions including
special functions and reserved words
(for example mv), for which ANOVA type tests are NOT required,