Here are very brief, Jain-orthodox meanings of these technical terms. In Jainism, these are categories used to describe how substances (dravya), their attributes (paryaya), and their essences relate to one another. The exact wording and emphasis can vary a little between Digambar and Shvetambar schools, but the core ideas are shared.

• Samyoga (समयोग)

- Meaning: the joining or union of things. In Jain philosophy, it often refers to the temporary contact or coexistence of different dravyas (for example, a soul associated with a body or a karmic particle associating with matter). It is a mode of conjunction that is not permanent in nature.

• Samavaya (समावय)

- Meaning: an inseparable, essential relation. This is the kind of relation that binds certain parts together so tightly that they cannot exist separately (e.g., the intrinsic link between a doṣa or quality and the substance it inherein). In Jain thought, samavaya explains why certain attributes or modifications are said to be inseparably attached to a substance.

• Tadatmya (तदात्म्य)

- Meaning: “that-essence” or the inherent identity of something. It designates the way a thing is essentially itself, in its own being — the self-identity or intrinsic character of a substance or mode, as understood within its own category.

• Svarupa Sambandha (स्वरूप संबंध)

- Meaning: the relation to one’s own form or inherent nature. “Svarupa” means the true nature or identity of a thing, and “sambandha” here refers to how that intrinsic nature is related to or manifested in the substance or its modifications. This is about understanding a thing in light of its own natural essence.

Notes

• Digambar and Shvetambar texts sometimes present slight variations in terminology or emphasis. The above aims to reflect the common core ideas in plain terms.
• If you want, I can provide a short, literal scriptural excerpt for each term (in the original Jain Sanskrit/Prakrit where available) along with a concise, orthodox meaning from Jain commentators.