refactor(library/simplifier): rewriter_rule_set

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
refactor(library/simplifier): cleanup rewrite_rule_set, and use it in the simplifier

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
fix(builtin/kernel): add ascii notation for transitivity

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>
chore(builtin/kernel): remove \bowtie as notation for transitivity

Signed-off-by: Leonardo de Moura <leonardo@microsoft.com>