Lemmas about subtraction in canonically ordered monoids #
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See lt_of_tsub_lt_tsub_right for a stronger statement in a linear order.
Lemmas that assume that an element is add_le_cancellable. #
        Lemmas where addition is order-reflecting. #
See add_tsub_le_assoc for an inequality.
See lt_tsub_iff_right for a stronger statement in a linear order.
See lt_tsub_iff_left for a stronger statement in a linear order.
See lt_of_tsub_lt_tsub_left for a stronger statement in a linear order.
See tsub_lt_tsub_iff_left_of_le for a stronger statement in a linear order.
See tsub_tsub_le for an inequality.
Lemmas in a canonically ordered monoid. #
Alias of the reverse direction of tsub_eq_zero_iff_le.
Lemmas where addition is order-reflecting. #
A canonically_ordered_add_monoid with ordered subtraction and order-reflecting addition is
cancellative. This is not an instance at it would form a typeclass loop.
See note [reducible non-instances].
Equations
- canonically_ordered_add_monoid.to_add_cancel_comm_monoid α = {add := add_comm_monoid.add (ordered_add_comm_monoid.to_add_comm_monoid α), add_assoc := _, add_left_cancel := _, zero := add_comm_monoid.zero (ordered_add_comm_monoid.to_add_comm_monoid α), zero_add := _, add_zero := _, nsmul := add_comm_monoid.nsmul (ordered_add_comm_monoid.to_add_comm_monoid α), nsmul_zero' := _, nsmul_succ' := _, add_comm := _}
 
Lemmas in a linearly canonically ordered monoid. #
See lt_tsub_iff_left_of_le_of_le for a weaker statement in a partial order.
This lemma also holds for ennreal, but we need a different proof for that.
See lt_tsub_iff_left_of_le_of_le for a weaker statement in a partial order.