Quadrilateral

Template

. . . . . And so on
. . . . . And so on
. . . . . And so on
. . . . . And so on

> . ? ! \
. . . . .
. . _ . .

> sets the direction, eastward.

. is a no-op

? requests a char input and pushes to stack.

! pops the top value of Stack and pushes character representation.

\ "deflects" the programs pointer, now facing southwestward.

. is a no-op.

_ is like an "angle of incidence-angle of reflection" operator. The pointer is now northwestward.

. is a no-op.

> does the same as the starting position

/\_| reflect the direction of the pointer, while <>v^ literally state it. ʌ may be used instead of ^, but is harder to type.

The number 0-9 are used to represent order.

0 1 2 v
v 4 3 <
> 5 6 v
v 8 7 <
> 9 . .

0 1 2 \
. . 3 .
. 4 . .
| . . .
. 5 . .
. . 6 .
. . . |
. . 7 .
. 8 . .
9 . . .

This program squares a number, prints the result, then starts again.

> ¿ & x \
. . . ! .
. . _ . .

Letter/Command	Function
`?`	Take character input and push to stack
`!`	Pop the Stack and print the character
`¿`	Take alphanumerical input and push to stack
`¡`	Pop the stack and print the number
`#`	Flip the top two stack items
`&`	Pop, then push the value twice
`=`	Pop twice, and if equal push 1, else 0
`%`	Pop twice, do first popped modulo second popped and Push to stack
`0-9`	Push the relative number to the stack
`+`	Pop twice, add and then push result
`-`	Pop twice, push first popped minus second popped
`*`	Pop twice, multiply, push to stack
`÷` or `:`, mainly `:`	Pop twice, divide first popped by second popped, push to stack
`$`	Pop the Stack, then do nothing
`@`	End the program elsewhere than a column or row overflow
`[`	Like brainfuck [, unless the instruction pointer is in some way facing east, then it is equivalent to brainfuck's ]
`]`	Like brainfuck ], unless the instruction pointer is in some way facing east, then it is equivalent to brainfuck's [
`u`	Like brainfuck [ if instruction pointer is some way facing south, brainfuck ], otherwise it is brainfuck's ]
`n`	Like brainfuck ] if instruction pointer is some way facing south, brainfuck [, otherwise it is brainfuck's [
`"`	Flip the stack
`'`	Roll the top item of stack to the bottom
`;`	Only at column 1. Comments the line
`~`	Pop twice, then push a random number between those two including both ends

So with that knowledge. Let's make a program to print a white space.

3 5 * 2 * 2 + !

Or more creatively:

3 5 * 2 \
. . . * .
. . 2 . .
. > + ! .

Or almost unreadable:

3 5 v . .
. . * . .
. . > 2 \
v 2 * < .
+ . . . .
> ! . . .