[SOLVED] How does one read iccr expression tables

[beeflobill]

I'm trying to read the expression tables given to my by iccr, but I do not see what I would expect from a Boolean table. I'm even confused by the tables in the ICC User Guide.

For example, the documentation had this table for the equation b & (c | d)

  b  & (c | d)
<1>    <2> <3>

hit  |  rval  |  <1> <2> <3>
----------------------------
  1  |    1   |   1    -    1
  1  |    1   |   1    1    1
  0  |    0   |   -    0    0
  1  |    0   |   0    -    -

I would expect to see 8 rows from a typical Boolean table in this case. How do they get away with 4, and what do the dashes mean?

 

[andyme]

"-" means don't care, or to say the value could be either 0 or 1. the table in your case covers all 8 possible combinations.

I'm trying to read the expression tables given to my by iccr, but I do not see what I would expect from a Boolean table. I'm even confused by the tables in the ICC User Guide.

For example, the documentation had this table for the equation b & (c | d)

  b  & (c | d)
<1>    <2> <3>

hit  |  rval  |  <1> <2> <3>
----------------------------
  1  |    1   |   1    -    1
  1  |    1   |   1    1    1
  0  |    0   |   -    0    0
  1  |    0   |   0    -    -

I would expect to see 8 rows in a typical Boolean table. How do they get away with 4, and what do the dashes mean?