पूर्वेण पश्चिमस्यानुपपत्तिर्व्याघातः ॥ कZ_०२.१०.५९ ॥
pūrveṇa paścimasyānupapattir vyāghātaḥ
‘Contradiction’ is when what comes later is not compatible with what was stated earlier.
It demands internal consistency: later clauses must not negate earlier clauses, otherwise the document becomes unenforceable or litigable.