If a party to an obligation gives notice to another, before the latter is in default, that he will not perform the same upon his part, and does not retract such notice before the time at which performance upon his part is due, such other party is entitled to enforce the obligation without previously performing, or offering to perform, any conditions on his part, in favor of the former party.
S.D. Codified Laws § 20-2-6
Performance of conditions waived by notice of nonperformance by other party
Source: CivC 1877, § 810; CL 1887, § 3433; RCivC 1903, § 1126; RC 1919, § 733; SDC 1939, § 47.0110.
Official source: South Dakota Legislature. Reproduced from public-domain South Dakota statutes; confirm against the official source for the current text. Not legal advice.