# [opencog-dev] Re: Soggy predicates

```
On 01/13/2017 03:26 PM, Nil Geisweiller wrote:
```
```Ben,

I only read it now, see my comments below.

On 12/14/2016 04:40 AM, Ben Goertzel wrote:
```
```A Simple Observation Grounded predicate, or Soggy predicate, is an
uncertain predicate F so that: For each x, the number F(x) lies in
[0,1] can be interpreted as the average degree to which an arbitrary
element of some set O of observations has property x.   (Here we
assume that the degree to which a specific observation has a property
x is itself a number in [0,1])
```
```
I guess what I would have written is:

"
```
For each x, the number F(x) lies in [0,1] and can be interpreted as the average degree to which an arbitrary element of x, some set of observations, has property F. (Here we assume that the degree to which a specific observation has a property F is itself a number in [0,1])
```"

```
So replaced O by x, then it makes complete sense, and don't even need to bring up the formal definition.
```
Nil

```
```
OK, but I think the definition for F(O) is missing, right?

I guess formally what we want is, given a universe U, define an
extension of F:U->[0,1] to PowerSet(U) such that

F(O) = weighted average of F(x) over O

or formally

F(O).s = Sum_x F(x).s * (Member x O).s / Sum_x (Member x O).s

right?

```
```EvaluationLink <s>
PredicateNode F
Atom x

as being equivalent to

Atom x
SatisfyingSet
PredicateNode F

Basically, this is just defining the membership function of the fuzzy set

SatisfyingSet
PredicateNode F

in a particular way.

We can then convert this ("M2I rule") to

Atom x
SatisfyingSet
PredicateNode F

because of the way F was originally defined.
```
```
Yes, this entails from the definition of the extension of F to PowerSet(U).

Apart from that formal omission, it's all clear. I'll add to the wiki
the definition of F extension, unless you disagree, then let me know why.

Nil
```
```
--
You received this message because you are subscribed to the Google Groups
"opencog" group.
To unsubscribe from this group and stop receiving emails from it, send an email