>>  <<  Usr  Pri  JfC  LJ  Phr  Dic  Voc  !:  Help  Dictionary

1. Mnemonics

The left side of the page shows an actual computer session with the result of each sentence shown at the left margin. First cover the comments at the right, and then attempt to state in English the meaning of each primitive so as to make clear the relations between related symbols. For example, “< is less than” and <. is lesser of (that is, minimum)”. Then uncover the comments and compare with your own.
```   7<5                        Less than
0                             A zero is interpreted as false.

7<.5                       Lesser of
5

7>5                        Greater than
1                             A one is true (à la George Boole)

7>.5                       Greater of
7

10^3                       Power (à la Augustus De Morgan)
1000

10^.1000                   Logarithm
3

7=5                        Equals
0

b=: 5                      Is (assignment or copula)
7<.b
5

Min=: <.                   Min is <.
power=: ^                  power is ^
gt=: >                     gt is >

10 power (5 Min 3)
1000
```

Exercises

1.1   Enter the following sentences on the computer, observe the results, give suitable names to any new primitives (such as * and +. and *.), and comment on their behaviour.

```   a=:0 1 2 3
b=:3 2 1 0
a+b
a*b
a-b
a%b
a^b
a^.b
a<b
a>b
(a<b)+(a>b)
(a<b)+.(a>b)
```