# Converting English to Boolean Algebra

1. Mar 31, 2009

### Nyasha

1. The problem statement, all variables and given/known data

An irrigation system should open sprinkler's water valve when if the system is enabled and neither raining nor freezing temperatures are detected.

2. Relevant equations

$$S\rightarrow$$ system enabled

$$R'\rightarrow$$ not raining

$$F'\rightarrow$$ freezing temperatures not detected

3. The attempt at a solution

F=S+R'F'

F=S+(RF)'

Guys l do not know if my Boolean equation is correct.

Last edited: Mar 31, 2009
2. Mar 31, 2009

### Redbelly98

Staff Emeritus
What are V and N?

Note there are 3 conditions (S, R', and F'), all of which must be true.

3. Mar 31, 2009

### Nyasha

It was actually supposed to be :

F=S+R'F'

F=S+(RF)'

So is this the correct equation ?

4. Mar 31, 2009

### LeeroyJenkins

An irrigation system should open sprinkler's water valve = Z
when if
the system is enabled = A
and
neither raining = B'
nor freezing temperatures are detected. (same as or not freeze...) = C'
Z = AB' + C'
as defined above the and is multiplication, the or is addition
if it says not, neither or something like that its the compliment

5. Mar 31, 2009

### Nyasha

So does "nor" mean that l should add the addition operation ? Would this be correct:

Z=A(B'+C') ?

Last edited: Apr 1, 2009
6. Apr 1, 2009

### Redbelly98

Staff Emeritus
I'm not sure if "+" means "and" or "or", so I'll just say it should be all and's, and no or's, in the statement.

I.e., there are 3 conditions A, B' and C', all of which must be true: A and B' and C'.

7. Apr 1, 2009

### Nyasha

Isn't the sprinkler's water valve supposed to open when system enabled and not raining or when the system is enabled and not freezing temperatures ?

F=A(B'+C')

F=AB'+AC'

"+" means or

"*" means and

' means NOT

8. Apr 1, 2009

### Redbelly98

Staff Emeritus
"neither raining nor freezing" means:
(Not raining) AND (Not freezing)​
which is equivalent to
Not (raining or freezing)​

9. Apr 1, 2009

### Nyasha

I know understand. You used Demorgan's law

B'C'=(B+C)'

Thanks very much for the help