Creates a level that fires when the supplied condition does not hold.
Examples
cl_not(cl_exact())
#> $method
#> [1] "not"
#>
#> $child
#> $method
#> [1] "exact"
#>
#> $term_frequency
#> [1] FALSE
#>
#> $is_null_level
#> [1] FALSE
#>
#> $is_else_level
#> [1] FALSE
#>
#> attr(,"class")
#> [1] "il_comparison_level"
#>
#> $is_null_level
#> [1] FALSE
#>
#> $is_else_level
#> [1] FALSE
#>
#> attr(,"class")
#> [1] "il_comparison_level"
