| Answer | Crossword Clue |
|---|---|
| RHO | Sigma's predecessor |
| ESSES | Sigmas |
| ESSES | Sigmas. |
| RHOS | Sigma's antecedents |
| TAU | Sigma's successor |
| CHI | Sigma's sweetheart |
| TAU | Sigma's follower |
| ESS | Sigma's sound |
| RHOS | They precede sigmas |
| PIS | Summations : sigmas :: products : ... |
| RHOS | Letters before sigmas |
| RHOS | Preceders of sigmas |
| RHOS | Predecessors of sigmas |
| TAUS | Greek letters after sigmas |
