.theorem {
    display: block;
    margin: 12px 0;
    font-style: italic;
    text-align:justify;
}
.theorem:before {
    content: "Theorem.";
    font-weight: bold;
    font-style: normal;
}
.prop {
    display: block;
    margin: 12px 0;
    font-style: italic;
    text-align:justify;
}
.prop:before {
    content: "Proposition.";
    font-weight: bold;
    font-style: normal;
}
.lemma {
    display: block;
    margin: 12px 0;
    font-style: italic;
    text-align:center;
}
.lemma:before {
    content: "Lemma.";
    font-weight: bold;
    font-style: normal;
}
.proof {
    display: block;
    margin: 12px 0;
    font-style: normal;
    text-align: left;
}
.proof:before {
    content: "Proof.";
    font-style: italic;
}
.proof:after {
    content: "\25FC";
    float:right;
}
.definition {
    display: block;
    margin: 12px 0;
    font-style: normal;
    text-align: justify;
}
.definition:before {
    content: "Definition.";
    font-weight: bold;
    font-style: normal;
}
.example {
    display: block;
    margin: 12px 0;
    font-style: normal;
    text-align: justify;
}
.example:before {
    content: "Example.";
    font-weight: bold;
    font-style: normal;
}