Related Clues:
- Make a difference
- Mathematician who used AND, OR and NOT
- Be relevant
- Algebra pioneer George
- Be of consequence
- ''Anti'' attachment
- Have significance
- Be important
- Symbolic logic pioneer George
- George who invented a logic system
- Physics concern
- See 4 Down
- Physical substance
- Substance or material - not spirit
- No . . . . . . - it is unimportant