\text{Simplify:}\mathrm{ 88}-1\times (5+12)-19

To simplify the given mathematical expression, we must follow the order of operations, often remembered by the acronym PEMDAS/BODMAS (Parentheses/Brackets, Exponents/Orders, Multiplication and Division, Addition and Subtraction). Let's solve it step-by-step.

The given expression is:

$88-1\times (5+12)-19$

Step 1: Simplify the expression inside the parentheses
First, perform the addition inside the parentheses:
$5+12=17$
Substitute this back into the expression:
$88-1\times 17-19$

Step 2: Perform the multiplication
Next, multiply 1 by 17:
$1\times 17=17$
Now the expression becomes:
$88-17-19$

Step 3: Perform subtraction from left to right
First, subtract 17 from 88:
$88-17=71$
Then, subtract 19 from 71:
$71-19=52$

Therefore, the simplified value of the expression is 52.