.pa 1
.he 'DC (I)'1/15/73'DC (I)'
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NAME		dc -- desk calculator
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SYNOPSIS	dc__ [file]
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DESCRIPTION	dc__
is an arbitrary precision integer arithmetic package.
The overall structure of dc is
a stacking (reverse Polish) calculator.
The following constructions are recognized
by the calculator:
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number
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The value of the number is pushed on the stack.
A number is an unbroken string of the digits 0-9.
It may be preceded by an underscore (_) to input a
negative number.
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+_ -_ *_ /_ %_ ^_
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The top two values on the stack are added (+_),
subtracted (-_), multiplied (*_), divided (/_),
remaindered (%_) or exponentiated (^).
The two entries are popped off the stack;
the result is pushed on the stack in their place.
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s_x
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The top of the stack is popped and stored into
a register named x, where x may be any character.
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l_x
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The value in register x is pushed on the stack.
The register x is not altered.
All registers start with zero value.
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d_
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The top value on the stack is pushed on the stack.
Thus the top value is duplicated.
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p_
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The top value on the stack is printed.
The top value remains unchanged.
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f_
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All values on the stack and in registers are printed.
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.ul 1
q
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exits the program. If executing a string, the nesting level is
popped by two.
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.ul
x
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treats the top element of the stack as a character string
and executes it as a string of dc commands.
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[...]_____
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puts the bracketed ascii string onto the top of the stack.
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<_x =_x >_x
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The top two elements of the stack are popped and compared.
Register x is executed if they obey the stated
relation.
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.ul
v
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replaces the top element on the stack by its square root.
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!_
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interprets the rest of the line as a UNIX command.
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c_
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All values on the stack are popped.
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i_
.br
The top value on the stack is popped and used as the
number radix for further input.
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o_
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the top value on the stack is popped and used as the
number radix for further output.
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z_
.br
the stack level is pushed onto the stack.
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?_
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a line of input is taken from the input source (usually the console)
and executed.
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new-line
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ignored except as the name of a register or to end the
response to a ?_.
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space
.br
ignored except as the name of a register or to terminate a number.
.br
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If a file name is given, input is taken from that file until
end-of-file, then input is taken from the console.
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An example to 
calculate the monthly, weekly and
hourly rates for a $10,000/year salary.
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10000
100*	(now in cents)
dsa	(non-destructive store)
12/	(pennies per month)
la52/	(pennies per week)
d10*	(deci-pennies per week)
375/	(pennies per hour)
f	(print all results)
     512
     19230
     83333
"a"  1000000
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An example which prints the first ten values of n! is
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[la1+dsa*pla10>x]sx
0sa1
lxx
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FILES		--
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SEE ALSO	msh(VII), salloc(III)
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DIAGNOSTICS	(x) ? for unrecognized character x.
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(x) ? for not enough elements on the stack to do what was asked
by command x.
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"Out of space" when the free list is exhausted (too many digits).
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"Out of headers" for too many numbers being kept around.
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"Out of pushdown" for too many items on the stack.
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"Nesting Depth" for too many levels of nested execution.
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BUGS		--