Crossword Help Forum
Forum Rules

I've been going ok with them lately, but this one stumped me.

Standard Clue:
Foundational building block (5)

Hard Clue:
Preliminary proof (5)

L _ M _ A

Verno, it looks like this, from Chambers

lemma1 /lem'ə/
noun (pl lemm'as or lemm'ata)
1. A preliminary proposition (mathematics)
2. A premise taken for granted (mathematics)
3. A theme, argument, heading or headword

Fits like a dream, and the grid has turned green!

Thanks mate!