module Term_literal:Term literals.sig
..end
val is_literal : Term.term -> bool
not (
Term.is_variable
t) || (is_literal l)
val variable : Term.term -> Term.term
variable l
is the variable contained in a literal term.
Term_literal.is_literal
l
Term.is_variable
(variable l)
val is_positive : Term.term -> bool
val literal : Term.term -> Term.term
literal v
is the positive literal term with variable v
.
Term.is_variable
v
Term_literal.is_positive
(literal v)
Term_literal.variable
(literal v) = v
val negation : Term.term -> Term.term
is_literal l
is_positive (negation l) = not (is_positive l)
variable (negation l) = variable l