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Unformatted text preview: nt of this world, which we call the “world
tool bar”. Immediately above the world is a tab which contains
the name of the world. Initially this is Untitled World.
The sentence panel is the white panel to the right of the window. At ﬁrst it contains only the numeral “1” inside. This is
where sentences are entered and evaluated to see whether they are
true or false in the world represented in the world window. Feel
free to type something in the sentence window, say, “I’d rather be
in Philadelphia.” Immediately above the sentences is a tab which
contains the name of the collection of sentences. Initially this is
14 Using Tarski’s World / 15 Figure 3.1: Main window of Tarski’s World.
The sentence toolbar appears above the sentence panel. We
generally use these tools to enter sentences of ﬁrst-order logic. Feel
free to play around by clicking on the buttons in the sentence
toolbar. 3.1.1 Opening saved ﬁles Both worlds and sentence lists can be saved as ﬁles on your disk.
Indeed, many prepackaged world and sentence ﬁles come with
Tarski’s World. To open a saved ﬁle, you use the Open. . . command on the File menu.
To open a ﬁle, pull down the File menu and choose Open. . . .
A ﬁle dialog will appear which allows you to navigate to the ﬁle that
you wish to open. You will have to navigate to the right folder to
ﬁnd the prepackaged ﬁles, which are in TW Exercise Files. Find this
folder, select it, and then click Open, or simply double-click on the
name. Feel free to open one of the ﬁles you see, say, Ackermann’s
World, but if you make any changes to the world, don’t save them.
When you open a ﬁle, a new tab will be created above the new
sentence or world panel.1 This tab will contain the name of the ﬁle
1 There is one exception to this rule, and that is when the current tab is
one of the “Untitled” tabs that has not been changed. In this case the old tab 16 / LPL Software Manual that you opened. To return to viewing any other world or sentence
ﬁle, just click on its tab, and it will reappear. 3.1.2 Starting new ﬁles If you want to start a new world or sentence ﬁle, choose New
from the File menu. You may then specify whether you want a
new world or new sentence ﬁle from the menu which appears. The
New World and New Sentences commands create a new empty
world or sentence panel as appropriate. These are created as new
tabs within the collection of worlds or sentences.
The command New Random World on the New menu creates a new world, and populates it with randomly chosen blocks.
The New Window item on the New menu creates a new
window identical to the initial main window.
You may have noticed that there is another New command on
the File menu. depending on which panel is active, this reads New
Sentences or New World, and is equivalent to the corresponding
item on the New submenu. This item also has a shortcut. 3.1.3 Saving a ﬁle If you want to save a ﬁle, use the Save submenu f...
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- Winter '14